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.

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

CHANGELOG item

Closes #18544

Signed-off-by: NRémy Coutable <remy@rymai.me>

This reverts commit 13e37a3e.

+ Move 'Edit Project/Group' out of membership-related partial
+ Show the access request buttons only to logged-in users
+ Put the request access buttons out of in a more visible button
+ Improve the copy in the #remove_member_message helper
Signed-off-by: NRémy Coutable <remy@rymai.me>

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

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

Prevent Groups to have smaller visibility than projects
Add default_group_visibility_level to configuration
Code improvements

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