Close #13539.

Co-authored by: @lunny @appleboy @fuxiaohei and others.

Related projects:
- https://gitea.com/gitea/actions-proto-def
- https://gitea.com/gitea/actions-proto-go
- https://gitea.com/gitea/act
- https://gitea.com/gitea/act_runner

### Summary

The target of this PR is to bring a basic implementation of "Actions",
an internal CI/CD system of Gitea. That means even though it has been
merged, the state of the feature is **EXPERIMENTAL**, and please note
that:

- It is disabled by default;
- It shouldn't be used in a production environment currently;
- It shouldn't be used in a public Gitea instance currently;
- Breaking changes may be made before it's stable.

**Please comment on #13539 if you have any different product design
ideas**, all decisions reached there will be adopted here. But in this
PR, we don't talk about **naming, feature-creep or alternatives**.

### ⚠️ Breaking

`gitea-actions` will become a reserved user name. If a user with the
name already exists in the database, it is recommended to rename it.

### Some important reviews

- What is `DEFAULT_ACTIONS_URL` in `app.ini` for?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1055954954
- Why the api for runners is not under the normal `/api/v1` prefix?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1061173592
- Why DBFS?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1061301178
- Why ignore events triggered by `gitea-actions` bot?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1063254103
- Why there's no permission control for actions?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1090229868

### What it looks like

<details>

#### Manage runners

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205870657-c72f590e-2e08-4cd4-be7f-2e0abb299bbf.png">

#### List runs

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205872794-50fde990-2b45-48c1-a178-908e4ec5b627.png">


#### View logs

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205872501-9b7b9000-9542-4991-8f55-18ccdada77c3.png">



</details>

### How to try it

<details>

#### 1. Start Gitea

Clone this branch and [install from
source](https://docs.gitea.io/en-us/install-from-source).

Add additional configurations in `app.ini` to enable Actions:

```ini
[actions]
ENABLED = true
```

Start it.

If all is well, you'll see the management page of runners:

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205877365-8e30a780-9b10-4154-b3e8-ee6c3cb35a59.png">


#### 2. Start runner

Clone the [act_runner](https://gitea.com/gitea/act_runner), and follow
the
[README](https://gitea.com/gitea/act_runner/src/branch/main/README.md)
to start it.

If all is well, you'll see a new runner has been added:

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205878000-216f5937-e696-470d-b66c-8473987d91c3.png">

#### 3. Enable actions for a repo

Create a new repo or open an existing one, check the `Actions` checkbox
in settings and submit.

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205879705-53e09208-73c0-4b3e-a123-2dcf9aba4b9c.png">
<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205879383-23f3d08f-1a85-41dd-a8b3-54e2ee6453e8.png">

If all is well, you'll see a new tab "Actions":

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205881648-a8072d8c-5803-4d76-b8a8-9b2fb49516c1.png">

#### 4. Upload workflow files

Upload some workflow files to `.gitea/workflows/xxx.yaml`, you can
follow the [quickstart](https://docs.github.com/en/actions/quickstart)
of GitHub Actions. Yes, Gitea Actions is compatible with GitHub Actions
in most cases, you can use the same demo:

```yaml
name: GitHub Actions Demo
run-name: ${{ github.actor }} is testing out GitHub Actions 🚀
on: [push]
jobs:
  Explore-GitHub-Actions:
    runs-on: ubuntu-latest
    steps:
      - run: echo "🎉 The job was automatically triggered by a ${{ github.event_name }} event."
      - run: echo "🐧 This job is now running on a ${{ runner.os }} server hosted by GitHub!"
      - run: echo "🔎 The name of your branch is ${{ github.ref }} and your repository is ${{ github.repository }}."
      - name: Check out repository code
        uses: actions/checkout@v3
      - run: echo "💡 The ${{ github.repository }} repository has been cloned to the runner."
      - run: echo "🖥️ The workflow is now ready to test your code on the runner."
      - name: List files in the repository
        run: |
          ls ${{ github.workspace }}
      - run: echo "🍏 This job's status is ${{ job.status }}."
```

If all is well, you'll see a new run in `Actions` tab:

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205884473-79a874bc-171b-4aaf-acd5-0241a45c3b53.png">

#### 5. Check the logs of jobs

Click a run and you'll see the logs:

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205884800-994b0374-67f7-48ff-be9a-4c53f3141547.png">

#### 6. Go on

You can try more examples in [the
documents](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions)
of GitHub Actions, then you might find a lot of bugs.

Come on, PRs are welcome.

</details>

See also: [Feature Preview: Gitea
Actions](https://blog.gitea.io/2022/12/feature-preview-gitea-actions/)

---------

Co-authored-by: a101211279 <1012112796@qq.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: ChristopherHX <christopher.homberger@web.de>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>

The `commit_id` property name is the same as equivalent functionality in
GitHub. If the action was not caused by a commit, an empty string is
used.

This can for example be used to automatically add a Resolved label to an
issue fixed by a commit, or clear it when the issue is reopened.

Previously, there was an `import services/webhooks` inside
`modules/notification/webhook`.
This import was removed (after fighting against many import cycles).
Additionally, `modules/notification/webhook` was moved to
`modules/webhook`,
and a few structs/constants were extracted from `models/webhooks` to
`modules/webhook`.

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>

This PR adds a context parameter to a bunch of methods. Some helper
`xxxCtx()` methods got replaced with the normal name now.

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

I found myself wondering whether a PR I scheduled for automerge was
actually merged. It was, but I didn't receive a mail notification for it
- that makes sense considering I am the doer and usually don't want to
receive such notifications. But ideally I want to receive a notification
when a PR was merged because I scheduled it for automerge.

This PR implements exactly that.

The implementation works, but I wonder if there's a way to avoid passing
the "This PR was automerged" state down so much. I tried solving this
via the database (checking if there's an automerge scheduled for this PR
when sending the notification) but that did not work reliably, probably
because sending the notification happens async and the entry might have
already been deleted. My implementation might be the most
straightforward but maybe not the most elegant.

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

Add support for triggering webhook notifications on wiki changes.

This PR contains frontend and backend for webhook notifications on wiki actions (create a new page, rename a page, edit a page and delete a page). The frontend got a new checkbox under the Custom Event -> Repository Events section. There is only one checkbox for create/edit/rename/delete actions, because it makes no sense to separate it and others like releases or packages follow the same schema.

![image](https://user-images.githubusercontent.com/121972/177018803-26851196-831f-4fde-9a4c-9e639b0e0d6b.png)

The actions itself are separated, so that different notifications will be executed (with the "action" field). All the webhook receivers implement the new interface method (Wiki) and the corresponding tests.

When implementing this, I encounter a little bug on editing a wiki page. Creating and editing a wiki page is technically the same action and will be handled by the ```updateWikiPage``` function. But the function need to know if it is a new wiki page or just a change. This distinction is done by the ```action``` parameter, but this will not be sent by the frontend (on form submit). This PR will fix this by adding the ```action``` parameter with the values ```_new``` or ```_edit```, which will be used by the ```updateWikiPage``` function.

I've done integration tests with matrix and gitea (http).

![image](https://user-images.githubusercontent.com/121972/177018795-eb5cdc01-9ba3-483e-a6b7-ed0e313a71fb.png)

Fix #16457

Signed-off-by: Aaron Fischer <mail@aaron-fischer.net>

* Move some files into models' sub packages

* Move functions

* merge main branch

* Fix check

* fix check

* Fix some tests

* Fix lint

* Fix lint

* Revert lint changes

* Fix error comments

* Fix lint

Co-authored-by: 6543 <6543@obermui.de>

Support synchronizing with the push mirrors whenever new commits are pushed or synced from pull mirror.

Related Issues: #18220

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

* Move access and repo permission to models/perm/access

* fix test

* fix git test

* Move functions sequence

* Some improvements per @KN4CK3R and @delvh

* Move issues related code to models/issues

* Move some issues related sub package

* Merge

* Fix test

* Fix test

* Fix test

* Fix test

* Rename some files

* Added package store settings.

* Added models.

* Added generic package registry.

* Added tests.

* Added NuGet package registry.

* Moved service index to api file.

* Added NPM package registry.

* Added Maven package registry.

* Added PyPI package registry.

* Summary is deprecated.

* Changed npm name.

* Sanitize project url.

* Allow only scoped packages.

* Added user interface.

* Changed method name.

* Added missing migration file.

* Set page info.

* Added documentation.

* Added documentation links.

* Fixed wrong error message.

* Lint template files.

* Fixed merge errors.

* Fixed unit test storage path.

* Switch to json module.

* Added suggestions.

* Added package webhook.

* Add package api.

* Fixed swagger file.

* Fixed enum and comments.

* Fixed NuGet pagination.

* Print test names.

* Added api tests.

* Fixed access level.

* Fix User unmarshal.

* Added RubyGems package registry.

* Fix lint.

* Implemented io.Writer.

* Added support for sha256/sha512 checksum files.

* Improved maven-metadata.xml support.

* Added support for symbol package uploads.

* Added tests.

* Added overview docs.

* Added npm dependencies and keywords.

* Added no-packages information.

* Display file size.

* Display asset count.

* Fixed filter alignment.

* Added package icons.

* Formatted instructions.

* Allow anonymous package downloads.

* Fixed comments.

* Fixed postgres test.

* Moved file.

* Moved models to models/packages.

* Use correct error response format per client.

* Use simpler search form.

* Fixed IsProd.

* Restructured data model.

* Prevent empty filename.

* Fix swagger.

* Implemented user/org registry.

* Implemented UI.

* Use GetUserByIDCtx.

* Use table for dependencies.

* make svg

* Added support for unscoped npm packages.

* Add support for npm dist tags.

* Added tests for npm tags.

* Unlink packages if repository gets deleted.

* Prevent user/org delete if a packages exist.

* Use package unlink in repository service.

* Added support for composer packages.

* Restructured package docs.

* Added missing tests.

* Fixed generic content page.

* Fixed docs.

* Fixed swagger.

* Added missing type.

* Fixed ambiguous column.

* Organize content store by sha256 hash.

* Added admin package management.

* Added support for sorting.

* Add support for multiple identical versions/files.

* Added missing repository unlink.

* Added file properties.

* make fmt

* lint

* Added Conan package registry.

* Updated docs.

* Unify package names.

* Added swagger enum.

* Use longer TEXT column type.

* Removed version composite key.

* Merged package and container registry.

* Removed index.

* Use dedicated package router.

* Moved files to new location.

* Updated docs.

* Fixed JOIN order.

* Fixed GROUP BY statement.

* Fixed GROUP BY #2.

* Added symbol server support.

* Added more tests.

* Set NOT NULL.

* Added setting to disable package registries.

* Moved auth into service.

* refactor

* Use ctx everywhere.

* Added package cleanup task.

* Changed packages path.

* Added container registry.

* Refactoring

* Updated comparison.

* Fix swagger.

* Fixed table order.

* Use token auth for npm routes.

* Enabled ReverseProxy auth.

* Added packages link for orgs.

* Fixed anonymous org access.

* Enable copy button for setup instructions.

* Merge error

* Added suggestions.

* Fixed merge.

* Handle "generic".

* Added link for TODO.

* Added suggestions.

* Changed temporary buffer filename.

* Added suggestions.

* Apply suggestions from code review

Co-authored-by: Thomas Boerger <thomas@webhippie.de>

* Update docs/content/doc/packages/nuget.en-us.md

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Thomas Boerger <thomas@webhippie.de>

Add new feature to delete issues and pulls via API

Co-authored-by: fnetx <git@fralix.ovh>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Gusted <williamzijl7@hotmail.com>
Co-authored-by: 6543 <6543@obermui.de>

We can't depend on `latest` version of gofumpt because the output will
not be stable across versions. Lock it down to the latest version
released yesterday and run it again.

* gofumpt -w -l .

* gofumpt -w -l -extra .

* Add linter

* manual fix

* change make fmt

This PR continues the work in #17125 by progressively ensuring that git
commands run within the request context.

This now means that the if there is a git repo already open in the context it will be used instead of reopening it.

Signed-off-by: Andrew Thornton <art27@cantab.net>

Remove repeated type declarations in function definitions.

* Some refactors related repository model

* Move more methods out of repository

* Move repository into models/repo

* Fix test

* Fix test

* some improvements

* Remove unnecessary function

* Move user related model into models/user

* Fix lint for windows

* Fix windows lint

* Fix windows lint

* Move some tests in models

* Merge

* make repo as "pending transfer" if on transfer start doer has no right to create repo in new destination

* if new pending transfer ocured, create UI & Mail notifications

* Add dismiss review feature

refs:
    https://github.blog/2016-10-12-dismissing-reviews-on-pull-requests/
    https://developer.github.com/v3/pulls/reviews/#dismiss-a-review-for-a-pull-request

* change modal ui and error message

* Add unDismissReview api

Signed-off-by: a101211279 <1012112796@qq.com>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>

Fixes #14187: mention handling extracted from email notification code
Fixes #14013: add notification for mentions in pull request code comments
Fixes #13450: Not receiving any emails with setting "Only Email on Mention"

Co-authored-by: Antoine GIRARD <sapk@users.noreply.github.com>

* Add field with isIssueWriter to front end

* Make branch field editable

* Switch frontend to form and POST from javascript

* Add /issue/id/ref endpoint to routes

* Use UpdateIssueTitle model to change ref in backend

* Removed crossreference check and adding comments on branch change

* Use ref returned from POST to update the field

* Prevent calling loadRepo from models/

* Branch/tag refreshed without page reload

* Remove filter for empty branch name

* Add clear option to tag list as well

* Delete button translation and coloring

* Fix for not showing selected branch name in new issue

* Check that branch is not being changed on a PR

* Change logic

* Notification when changing issue ref

* Fix for renamed permission parameter

* Fix for failing build

* Apply suggestions from code review

Co-authored-by: zeripath <art27@cantab.net>

Co-authored-by: Gitea <gitea@fake.local>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

* Add push commits history comment on PR time-line
* Add notify by email and ui of this comment type also

Signed-off-by: a101211279 <1012112796@qq.com>

* Add migrations for IsForcePush
* fix wrong force-push judgement
* Apply suggestions from code review
* Remove commit number check
* add own notify fun
* fix some typo

Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>

* fix lint

* fix style again, I forgot something before

* Change email notify way

* fix api

* add number check if It's force-push

* Add repo commit link fuction
remove unnecessary check
skip show push commits comment which not have commits alive

* Update issue_comment.go

* Apply suggestions from code review

Co-authored-by: mrsdizzie <info@mrsdizzie.com>

* Apply suggestions from code review

* fix ui view

Co-authored-by: silverwind <me@silverwind.io>

* fix height

* remove unnecessary style define

* simplify GetBranchName

* Apply suggestions from code review

* save commit ids and isForce push by json
* simplify GetBranchName

* fix bug

Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>
Co-authored-by: mrsdizzie <info@mrsdizzie.com>
Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: silverwind <me@silverwind.io>

Signed-off-by: Andrew Thornton <art27@cantab.net>

* add request review feature in pull request

add a way to notify specific reviewers to review like github , by add  or delet a  special type
review . The acton is  is similar to Assign ,  so many code reuse the function and items of
Assignee, but the meaning and result is different.

The Permission style is is similar to github, that only writer can add a review request from Reviewers,
but the poster can recall and remove a review request after a reviwer has revied even if he don't have
Write Premission. only manager , the poster and reviewer of a request review can remove it.

The reviewers can be requested to review contain all readers for private repo , for public, contain
all writers and watchers.

The offical Review Request will block merge if Reject can block it.

an other change: add ui otify for Assignees.

Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>
Co-authored-by: Lauris BH <lauris@nix.lv>

Signed-off-by: a101211279 <1012112796@qq.com>

* new change

* add placeholder string

* do some changes follow #10238 to add review requests num on lists also
change icon for review requests to eye

Co-authored-by: Lauris BH <lauris@nix.lv>

* Move push commits from models to modules/repository

* fix test

* fix test

* fix test

* fix test

* fix test

Co-authored-by: zeripath <art27@cantab.net>

* Adds functionality to change target branch of created pull requests

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Use const instead of var in JavaScript additions

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Check if branches are equal and if PR already exists before changing target branch

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Make sure to check all commits

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Print error messages for user as error flash message

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Disallow changing target branch of closed or merged pull requests

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Resolve conflicts after merge of upstream/master

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Change order of branch select fields

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Removes duplicate check

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Use ctx.Tr for translations

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Recompile JS

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Use correct translation namespace

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Remove redundant if condition

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Moves most change branch logic into pull service

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Completes comment

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Add Ref to ChangesPayload for logging changed target branches
instead of creating a new struct

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Revert changes to go.mod

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Directly use createComment method

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Return 404 if pull request is not found. Move written check up

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Remove variable declaration

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Return client errors on change pull request target errors

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Return error in commit.HasPreviousCommit

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Adds blank line

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Test patch before persisting new target branch

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Update patch before testing (not working)

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Removes patch calls when changeing pull request target

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Removes unneeded check for base name

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Moves ChangeTargetBranch completely to pull service. Update patch status.

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Set webhook mode after errors were validated

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Update PR in one transaction

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Move logic for check if head is equal with branch to pull model

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Adds missing comment and simplify return

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Adjust CreateComment method call

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Refactor comment

* fix test

* improve code

* Move mirror sync actions to notification

* fix lint

* move transfer repository and rename repository on a service package and start action notification

* remove unused codes

* fix lint

* fix bugs

* fix test

* fix test

* fix test

* fix lint

* update go mod and sum

* Move some actions to notification/action

* Fix test

* fix test

* Move pull webhook to notification

* fix fmt

* Move push commits events to notification

* Update modules/notification/base/null.go

Co-Authored-By: guillep2k <18600385+guillep2k@users.noreply.github.com>

* Send email to assigned user

* Only send mail if enabled

* Mail also when assigned through API

* Need to refactor functions from models to issue service

* Refer to issue index rather than ID

* Disable email notifications completly at initalization if global disable

* Check of user enbled mail shall be in mail notification function only

* Initialize notifications from routers init function.

* Use the assigned comment when sending assigned mail

* Refactor so that assignees always added as separate step when new issue/pr.

* Check error from AddAssignees

* Check if user can be assiged to issue or pull request

* Missing return

* Refactor of CanBeAssigned check.

CanBeAssigned shall have same check as UI.

* Clarify function names (toggle rather than update/change), and clean up.

* Fix review comments.

* Flash error if assignees was not added when creating issue/pr

* Generate error if assignee users doesn't exist

* move clearlabels from models to issue service

* improve code

* Apply suggestions from code review

Co-Authored-By: zeripath <art27@cantab.net>

* move code.gitea.io/git to code.gitea.io/gitea/modules/git

* fix imports

* fix fmt

* fix misspell

* remove wrong tests data

* fix unit tests

* fix tests

* fix tests

* fix tests

* fix tests

* fix tests

* enable Debug to trace the failure tests

* fix tests

* fix tests

* fix tests

* fix tests

* fix tests

* comment commit count tests since git clone depth is 50

* fix tests

* update from code.gitea.io/git

* revert change to makefile

* notification for indexer

* use NullNotifier as parent struct

* mail notification implement interface

* fix file comment year

* use NullNotifier as parent struct of notifiers

* add notification interface and refactor UI notifications

* add missing methods on notification interface and notifiy only issue status really changed

* implement NotifyPullRequestReview for ui notification

* Notification - Step 1

* Add copyright headers

* Cache issue and repository on notification model