This PR introduces a new UI element type for Gitea called `flex-item`.
It consists of a horizontal card with a leading, main and trailing part:


![grafik](https://github.com/go-gitea/gitea/assets/47871822/395dd3f3-3906-4481-8f65-be6ac0acbe03)

The idea behind it is that in Gitea UI, we have many cases where we use
this kind of layout, but it is achieved in many different ways:
  - grid layout
  - `.ui.list` with additional hacky flexbox
- `.ui.key.list` - looks to me like a style set originally created for
ssh/gpg key list, was used in many other places
  - `.issue.list` - created for issue cards, used in many other places
  - ...

This new style is based on `.issue.list`, specifically the refactoring
of it done in #25750.

In this PR, the new element is introduced and lots of templates are
being refactored to use that style. This allows to remove a lot of
page-specific css, makes many of the elements responsive or simply
provides a cleaner/better-looking way to present information.

A devtest section with the new style is also available.

<details>
<summary>Screenshots (left: before, right: after)</summary>

![Bildschirmfoto vom 2023-07-09
21-01-21](https://github.com/go-gitea/gitea/assets/47871822/545b7da5-b300-475f-bd6d-b7d836950bb5)
![Bildschirmfoto vom 2023-07-09
21-01-56](https://github.com/go-gitea/gitea/assets/47871822/b6f70415-6795-4f71-a5ea-117d56107ea1)
![Bildschirmfoto vom 2023-07-09
21-02-45](https://github.com/go-gitea/gitea/assets/47871822/47407121-3f2a-4778-8f6d-ad2687c2e7b3)
![Bildschirmfoto vom 2023-07-09
21-03-44](https://github.com/go-gitea/gitea/assets/47871822/76167aaf-c3b2-46f6-9ffd-709f20aa6a34)
![Bildschirmfoto vom 2023-07-09
21-04-52](https://github.com/go-gitea/gitea/assets/47871822/af8fdde5-711e-4524-99cf-fb5d68af85b9)
![Bildschirmfoto vom 2023-07-09
21-05-25](https://github.com/go-gitea/gitea/assets/47871822/ae406946-e3e4-4109-abfe-b3588a07b468)
![Bildschirmfoto vom 2023-07-09
21-06-35](https://github.com/go-gitea/gitea/assets/47871822/2dbacc04-24d6-4f91-9e42-e16d6e4b5f1f)
![Bildschirmfoto vom 2023-07-09
21-09-03](https://github.com/go-gitea/gitea/assets/47871822/d3ca4e56-a72f-4179-adc8-98bfd638025b)
![Bildschirmfoto vom 2023-07-09
21-09-44](https://github.com/go-gitea/gitea/assets/47871822/df1fa689-499c-4e54-b6fb-3b81644b725f)
![Bildschirmfoto vom 2023-07-09
21-10-27](https://github.com/go-gitea/gitea/assets/47871822/b21cac71-a85a-4c8c-bb99-ab90373d8e09)
![Bildschirmfoto vom 2023-07-09
21-11-12](https://github.com/go-gitea/gitea/assets/47871822/89be39cf-0af9-4f2d-9fca-42f9eb5e7824)
![Bildschirmfoto vom 2023-07-09
21-12-01](https://github.com/go-gitea/gitea/assets/47871822/079579ea-1ecb-49c0-b32b-b59ed957caec)
![Bildschirmfoto vom 2023-07-09
21-17-44](https://github.com/go-gitea/gitea/assets/47871822/61ac6ec4-a319-4d5c-9c99-2e02a77295ba)
![Bildschirmfoto vom 2023-07-09
21-18-27](https://github.com/go-gitea/gitea/assets/47871822/5b55b73f-6244-47f7-a3e6-c5e4a7474585)
![Bildschirmfoto vom 2023-07-09
21-19-18](https://github.com/go-gitea/gitea/assets/47871822/c1b7c22e-3e5a-46d4-b8d6-5560db478c0b)
![Bildschirmfoto vom 2023-07-09
21-29-13](https://github.com/go-gitea/gitea/assets/47871822/82ffca8d-ab2e-4a18-9954-5b685bf6a422)
![Bildschirmfoto vom 2023-07-09
21-30-11](https://github.com/go-gitea/gitea/assets/47871822/ad2fdccc-2be8-41bb-bfdc-a084aa387b61)
![Bildschirmfoto vom 2023-07-09
21-32-44](https://github.com/go-gitea/gitea/assets/47871822/2d298ba7-d084-48b5-a139-f86d56262110)
![Bildschirmfoto vom 2023-07-09
21-33-28](https://github.com/go-gitea/gitea/assets/47871822/4cbd838e-9de8-4ad0-8ed9-438da5c9a5cb)


</details>

---------

Co-authored-by: Giteabot <teabot@gitea.io>

Resolves #25057

This adds a E-Mail field to Organisations. The E-Mail is just shown on
the Profile when it is visited by a logged in User. The E-mail is not
used for something else.

**Screenshots:**

![grafik](https://github.com/go-gitea/gitea/assets/15185051/a8d622b3-7278-4c08-984b-9c5ebfdb5471)

![grafik](https://github.com/go-gitea/gitea/assets/15185051/6dcb1dd7-d04b-49eb-bc96-6582cfe9757b)

---------

Co-authored-by: Denys Konovalov <kontakt@denyskon.de>
Co-authored-by: Denys Konovalov <privat@denyskon.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>

This has recently regressed it seems. Put it back into same position as
https://github.com/go-gitea/gitea/pull/24345.

Clarify the "link-action" behavior:

>  // A "link-action" can post AJAX request to its "data-url"
> // Then the browser is redirect to: the "redirect" in response, or
"data-redirect" attribute, or current URL by reloading.

And enhance the "link-action" to support showing a modal dialog for
confirm. A similar general approach could also help PRs like
https://github.com/go-gitea/gitea/pull/22344#discussion_r1062883436

> // If the "link-action" has "data-modal-confirm(-html)" attribute, a
confirm modal dialog will be shown before taking action.


And a lot of duplicate code can be removed now. A good framework design
can help to avoid code copying&pasting.

---------

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

- Fix and improve mobile navbar layout
- Apply all cleanups suggested in
https://github.com/go-gitea/gitea/pull/25111
- Make media query breakpoints match Fomantic's exactly
- Clean up whitespace in class on navbar items

Mobile navbar before and after:
<img width="745" alt="Screenshot 2023-06-08 at 08 40 56"
src="https://github.com/go-gitea/gitea/assets/115237/ca84b239-b10f-41db-8c06-dcf2b6dd9d28">
<img width="739" alt="Screenshot 2023-06-08 at 08 41 23"
src="https://github.com/go-gitea/gitea/assets/115237/09133c54-eb7e-4110-858c-ead23c3b7521">

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>

Reorganize various CSS files for clarity, group together by subdirectory
in `index.css`. This reorders some of the rules, but I don't think it
should introduce any issues because of that.

Clean up a few cases where avatar dimensions were overwritten via CSS,
which were no longer needed or were possible to set via HTML width.

Also included are two small fixes:

- Fix one more case of incorrect avatar offset on review timeline
- Vertically center avatars in review sidebar

There is more to be done here, but some of the work depends on Fomantic
`comment` module removal, or in the case of org member lists, a refactor
of the `avatarlink` template to accept a size.

<img width="371" alt="image"
src="https://github.com/go-gitea/gitea/assets/115237/9c5902fb-2b89-4a7d-a152-60e74c3b2c56">
<img width="306" alt="image"
src="https://github.com/go-gitea/gitea/assets/115237/c8d92e2a-91c9-4f4a-a7de-6ae1a6bc0479">

---------

Co-authored-by: Giteabot <teabot@gitea.io>

Fix regression from https://github.com/go-gitea/gitea/pull/24471 where
CSS rules for `.icon.grey` were removed which were in use by the RSS
icons.

Gave them their own class instead, removed a wrapper and also fixed
vertical alignment on them. Additionally, did a few related fixes on the
org header for alignment.

Fixes: https://github.com/go-gitea/gitea/issues/24584

<img width="196" alt="Screenshot 2023-05-01 at 22 39 40"
src="https://user-images.githubusercontent.com/115237/235528228-959e2385-c1d2-4d5c-baec-e3784d459653.png">
<img width="216" alt="Screenshot 2023-05-01 at 22 44 20"
src="https://user-images.githubusercontent.com/115237/235528231-95cbff86-5672-48eb-b214-8bdcefa1612c.png">
<img width="120" alt="Screenshot 2023-05-01 at 22 56 36"
src="https://user-images.githubusercontent.com/115237/235529844-b94ab554-3259-4d0c-b040-82aed7d1a111.png">


<img width="372" alt="Screenshot 2023-05-01 at 22 54 25"
src="https://user-images.githubusercontent.com/115237/235529744-1a9c201b-5692-4122-9765-2f201a322a9e.png">
<img width="477" alt="Screenshot 2023-05-01 at 22 55 28"
src="https://user-images.githubusercontent.com/115237/235529748-62188554-9927-42ef-bc94-7052bce266e2.png">

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

Close #24302 
Part of #24229, Follows #24246
This PR focused on CSS style fine-tune, main changes:

1. Give `.ui.ui.ui.container` a width of `1280px` with a max-width of
`calc(100vw - 64px)`, so the main contents looks better on large
devices.

2. Share styles for table elements in all levels settings pages to fix
overflow of runners table on mobile and for consistency (The headers on
mobile can be further improved, but haven't found a proper way yet).

3. Use [stackable
grid](https://fomantic-ui.com/collections/grid.html#stackable) and
[device column width](https://fomantic-ui.com/examples/responsive.html)
for responsiveness for some pages (repo/org collaborators settings
pages, org teams related page)

4. Fixed #24302 by sharing label related CSS in reporg.css

5. Fine tune repo tags settings page

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

Close #24108

Use secondary pointing menu for tabs on user/organization home page so
the tabs look the same.
Main changes:
1. modified a part of dom structure in
`templates/user/overview/header.tmpl` to make it the same as
`templates/org/header.tmpl` in order to produce the same ui.
2. Move some css to `web_src/css/shared/repoorgshared.css` to make them
shareable between `templates/user/overview/header.tmpl` and
`templates/org/header.tmpl`

After:


https://user-images.githubusercontent.com/17645053/232400617-2add5bec-d483-4ab1-b48d-eaee157f7b09.mov

For further improvements. Need some thoughts: 

For [this
TODO](729ad294cb/templates/user/overview/header.tmpl (L1),)
it is viable to make it a shared template for [this
part](729ad294cb/templates/user/overview/header.tmpl (L2-L17))
and [this
part](729ad294cb/templates/org/header.tmpl (L1-L16))
because they are the same except for the variable. But for the menu
parts, they are quite different so might not be suitable to use a shared
template. So need some thoughts and advice about extracting the shared
template from these two headers.

---------

Co-authored-by: Giteabot <teabot@gitea.io>

Few fixes/enhancements around org pages:

Use flexbox for member and repo lists and tweak rendering of tabs and
list:

<img width="765" alt="Screenshot 2023-04-03 at 22 54 24"
src="https://user-images.githubusercontent.com/115237/229625716-92a834c3-9121-4729-8b9b-3a3973cf9a91.png">
<img width="771" alt="Screenshot 2023-04-03 at 22 55 15"
src="https://user-images.githubusercontent.com/115237/229625719-acc08ce8-4489-44a6-a9b9-e36755c55b1d.png">

Vertically center remove/leave buttons, add link to avatar:

<img width="1223" alt="Screenshot 2023-04-03 at 21 51 20"
src="https://user-images.githubusercontent.com/115237/229612616-b662b795-e754-41a1-a77a-381c267e6104.png">

Ran most of the Less files through the Less compiler and Prettier and
then followed up with a round of manual fixes.

The Less compiler had unfortunately stripped all `//` style comments
that I had to restore (It did preserve `/* */` comments). Other fixes
include duplicate selector removal which were revealed after the
transpilation and which weren't caught by stylelint before but now are.

Fixes: https://github.com/go-gitea/gitea/issues/15565