## Changes
- Adds the following high level access scopes, each with `read` and
`write` levels:
    - `activitypub`
    - `admin` (hidden if user is not a site admin)
    - `misc`
    - `notification`
    - `organization`
    - `package`
    - `issue`
    - `repository`
    - `user`
- Adds new middleware function `tokenRequiresScopes()` in addition to
`reqToken()`
  -  `tokenRequiresScopes()` is used for each high-level api section
- _if_ a scoped token is present, checks that the required scope is
included based on the section and HTTP method
  - `reqToken()` is used for individual routes
- checks that required authentication is present (but does not check
scope levels as this will already have been handled by
`tokenRequiresScopes()`
- Adds migration to convert old scoped access tokens to the new set of
scopes
- Updates the user interface for scope selection

### User interface example
<img width="903" alt="Screen Shot 2023-05-31 at 1 56 55 PM"
src="https://github.com/go-gitea/gitea/assets/23248839/654766ec-2143-4f59-9037-3b51600e32f3">
<img width="917" alt="Screen Shot 2023-05-31 at 1 56 43 PM"
src="https://github.com/go-gitea/gitea/assets/23248839/1ad64081-012c-4a73-b393-66b30352654c">

## tokenRequiresScopes  Design Decision
- `tokenRequiresScopes()` was added to more reliably cover api routes.
For an incoming request, this function uses the given scope category
(say `AccessTokenScopeCategoryOrganization`) and the HTTP method (say
`DELETE`) and verifies that any scoped tokens in use include
`delete:organization`.
- `reqToken()` is used to enforce auth for individual routes that
require it. If a scoped token is not present for a request,
`tokenRequiresScopes()` will not return an error

## TODO
- [x] Alphabetize scope categories
- [x] Change 'public repos only' to a radio button (private vs public).
Also expand this to organizations
- [X] Disable token creation if no scopes selected. Alternatively, show
warning
- [x] `reqToken()` is missing from many `POST/DELETE` routes in the api.
`tokenRequiresScopes()` only checks that a given token has the correct
scope, `reqToken()` must be used to check that a token (or some other
auth) is present.
   -  _This should be addressed in this PR_
- [x] The migration should be reviewed very carefully in order to
minimize access changes to existing user tokens.
   - _This should be addressed in this PR_
- [x] Link to api to swagger documentation, clarify what
read/write/delete levels correspond to
- [x] Review cases where more than one scope is needed as this directly
deviates from the api definition.
   - _This should be addressed in this PR_
   - For example: 
   ```go
	m.Group("/users/{username}/orgs", func() {
		m.Get("", reqToken(), org.ListUserOrgs)
		m.Get("/{org}/permissions", reqToken(), org.GetUserOrgsPermissions)
}, tokenRequiresScopes(auth_model.AccessTokenScopeCategoryUser,
auth_model.AccessTokenScopeCategoryOrganization),
context_service.UserAssignmentAPI())
   ```

## Future improvements
- [ ] Add required scopes to swagger documentation
- [ ] Redesign `reqToken()` to be opt-out rather than opt-in
- [ ] Subdivide scopes like `repository`
- [ ] Once a token is created, if it has no scopes, we should display
text instead of an empty bullet point
- [ ] If the 'public repos only' option is selected, should read
categories be selected by default

Closes #24501
Closes #24799

Co-authored-by: Jonathan Tran <jon@allspice.io>
Co-authored-by: Kyle D <kdumontnu@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>

This PR adds the support for scopes of access tokens, mimicking the
design of GitHub OAuth scopes.

The changes of the core logic are in `models/auth` that `AccessToken`
struct will have a `Scope` field. The normalized (no duplication of
scope), comma-separated scope string will be stored in `access_token`
table in the database.
In `services/auth`, the scope will be stored in context, which will be
used by `reqToken` middleware in API calls. Only OAuth2 tokens will have
granular token scopes, while others like BasicAuth will default to scope
`all`.
A large amount of work happens in `routers/api/v1/api.go` and the
corresponding `tests/integration` tests, that is adding necessary scopes
to each of the API calls as they fit.


- [x] Add `Scope` field to `AccessToken`
- [x] Add access control to all API endpoints
- [x] Update frontend & backend for when creating tokens
- [x] Add a database migration for `scope` column (enable 'all' access
to past tokens)

I'm aiming to complete it before Gitea 1.19 release.

Fixes #4300

Close #14601
Fix #3690

Revive of #14601.
Updated to current code, cleanup and added more read/write checks.

Signed-off-by: Andrew Thornton <art27@cantab.net>
Signed-off-by: Andre Bruch <ab@andrebruch.com>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Norwin <git@nroo.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>