This will also work better for when the title makes the buttons drop down a new line

Closes #14228

Currently this works by loading the HAML partials via XHR. While this is
not the nicest setup it _is_ the easiest setup using the tools we
currently have.

Loading this data asynchronously doesn't make loading the related
MRs/branches itself faster, it merely ensures that loading the issue
itself is not slowed down.

Fixes gitlab-org/gitlab-ce#14949

Closes #13878

Closes #14195

Unified the 'edited text' to be the same in descriptions and comments

Closes #5538

Button full width on phone on MR/issue.

Closes #13771

Prior, it would only be shown if the issue had been edited.

Change edited icon to word.
Change edited text color to gray
cc/ @creamzy

Fix subtitles on minimize.
Fix styles for show.

[WIP]

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

A limited number of pages have defined their own descriptions, but
otherwise we default to the Project's description (if `@project` is
set), or the old `brand_title` fallback.

The image will either be the uploaded project icon (never a generated
one), the user's uploaded icon or Gravatar, or, finally, the GitLab
logo.

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>