Converted storage details into a small partial
Reworded the storage details summary as suggested
Updated pot file

- Remove `FeatureConstrainer` call wrapping api endpoint
- Remove `Feature.enabled?(:graphql)` conditionals in back and frontend
- Modify graphql test to be graphql flag agnostic
- Remove api routing spec
- Remove frontend feature flag via `gon`

This is a port MR for CE

Original MR:

https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14141

Inside a subgroup scope, when the user clicks on the
search drop down in the header, some options are displayed.

Some of this links direct the user to the issues and merge
requests linked to the subgroup. Nevertheless, the url
was broken because they doesn't include the complete
group namespace

Removes EE differences for app/views/admin/users/show.html.haml

Closes gitlab-ee#12533

See merge request gitlab-org/gitlab-ce!30407

Removes EE differences for app/views/layouts/fullscreen.html.haml

Closes gitlab-ee#12550

See merge request gitlab-org/gitlab-ce!30403

Create private merge requests in forks

Closes #58583

See merge request gitlab-org/gitlab-ce!29984

Removes EE differences for app/views/profiles/preferences/show.html.haml

Closes gitlab-ee#12553

See merge request gitlab-org/gitlab-ce!30397