This presenter will be used in an upcoming MR which adds
rendering of epic events on group activity page.

Adds suffix to enum methods and changes `in_groups` to
`of_groups`

There is a combination of few strategies implemented here:

1. Few relations were eager loaded
2. Changed few polymorphic routes to specific ones so we don't have to
   use `#becomes(Namespace)` which doesn't preserve association cache

Partially addresses #47424.

This changes the style of push events that remove tags or branches so
they don't display the commit details. This prevents displaying commit
details such as:

    000000 . --broken encoding

Instead we now simply display the header such as:

    Administrator deleted branch example-branch

This is displayed in the same style as events for newly created
branches/tags.

This commit also ensures that if no commit message is present we simply
don't display anything, instead of "--broken encoding".

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/36685
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/36722

Use the EnforcedStyleForMultiline: no_comma option.
Signed-off-by: NRémy Coutable <remy@rymai.me>

Improved todo message when an issue is assigned to yourself.
- The new message when an user assign to himself an issue or a mr is: "You
assigned issue xx to yourself"
- The new message when an user adds a todo to himself is: "You added a
todo for issue xx"
- The new message when and user mention himself is: "You mentioned
yourself on issue xx"
- The new message when an user directly address himself is: "You
directly addressed yourself on issue xx"
- The new message when an user mark himself as an approver is: "You set
yourself as an approver for merge request xx"

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/29425

fix features_visibility_spec.rb

remove strange part of spec

fix conditions of comments tab disappearing and fix spec

generate changelog

rewrite spec for more coplex check step-by-step

move conditional logic into helper and fix changelog

fix indentation in helper

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

Return a non-html-safe, unescaped String instead of ActiveSupport::SafeBuffer
to preserve safety when the output is misused. Currently there's oly one user,
which does the right thing.

Closes #23311

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb