* Add Icon URL to Backend

* Template for Icon URL

* Localization & Edit Icon URL

* Improve Custom Icon URL

* Removed not working else

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

* Disable SSH key addition and deletion when externally managed

When a user has a login source which has SSH key management
key addition and deletion using the UI should be disabled.

Fix #13983

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

* Make only externally managed keys disabled

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

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

* Standardize Co-Authored-By / Reviewed-By strings

* Use lowercase variant

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

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

Saying "this issue" is confusing because it could be understood as the
issue that the user is currently viewing, not which the "issue" link
points to.

* Diff stat improvements

- Combine number to just total number of changes
- Add tooltip over stats bar
- Increase contrast on file name
- Refactor classes and CSS to be more reusable

* misc tweaks

* make count bold

* add pull request command line instructions

* Add pull request manually merge instuction

* Fix styles

* Fix lint

* Move inline style to class file

* add space between merge button and hint text

* Add sentence end charcter

* Change the language file

* adjust secondary bg

* further adjustment

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

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

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

* Correct oauth signup title

When linking accounts, a password is not required anymore,
so this string becomes confusing

* string "remenber me": be more precise

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

* Improve error feedback for duplicate deploy keys

Instead of a generic HTTP 500 error page, a flash message is rendered
with the deploy key page template so inform the user that a key with the
intended title already exists.

* API returns 422 error when key with name exists

* Add email validity checking

Add email validity checking for the following routes:
[Web interface]
1. User registration
2. User creation by admin
3. Adding an email through user settings
[API]
1. POST /admin/users
2. PATCH /admin/users/:username
3. POST /user/emails

* Add further tests

* Add signup email tests

* Add email validity check for linking existing account

* Address PR comments

* Remove unneeded DB session

* Move email check to updateUser

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