The status is shown for
- The author of a commit when viewing a commit
- Notes on a commit (regular/diff)
- The user that triggered a pipeline when viewing a pipeline
- The author of a merge request when viewing a merge request
- The author of notes on a merge request (regular/diff)
- The author of an issue when viewing an issue
- The author of notes on an issue
- The author of a snippet when viewing a snippet
- The author of notes on a snippet
- A user's profile page
- The list of members of a group/user

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/40543
Bug introduced in
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15192

This commit alters views for the following models to use the markdown cache if
present:

* AbuseReport
* Appearance
* ApplicationSetting
* BroadcastMessage
* Group
* Issue
* Label
* MergeRequest
* Milestone
* Project

At the same time, calls to `escape_once` have been moved into the `single_line`
Banzai pipeline, so they can't be missed out by accident and the work is done
at save, rather than render, time.

Rearranged datetime created line

Added `avatar_class` option to `link_to_member` so it can be hidden

Made snippet title font heavier

Added file title  bar

Hidden unneeded info from xs screens

Added visibility icon

Reveal file-actions on xs screens

Added comments icon to snippets list items

Refactored no-comments declaration into framework stylesheet

Final touch ups

Fixed snippets_spec

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

This ensures all these calls have an author set, allowing the use of
"all" mentions where possible.

Closes #14328