Ports changes from https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/642 back into CE

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

This adds counters for build artifacts and LFS objects, and moves
the preexisting repository_size and commit_count from the projects
table into a new project_statistics table.

The counters are displayed in the administration area for projects
and groups, and also available through the API for admins (on */all)
and normal users (on */owned)

The statistics are updated through ProjectCacheWorker, which can now
do more granular updates with the new :statistics argument.

Restore changes for api spec files

Fix error in rspec Users

Delete extra space Repositories-spec

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

Restore changes for api spec files

Fix error in rspec Users

Delete extra space Repositories-spec

See https://gitlab.com/gitlab-org/gitlab-ce/issues/24386

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

API: Share projects only with groups current_user can access

Aims to address the issues here: https://gitlab.com/gitlab-org/gitlab-ce/issues/23004

* Projects can be shared with non-existent groups
* Projects can be shared with groups that the current user does not have access to read

Concerns:

The new implementation of the API endpoint allows projects to be shared with a larger range of groups than can be done via the web UI.

The form for sharing a project with a group uses the following API endpoint to index the available groups: https://gitlab.com/gitlab-org/gitlab-ce/blob/494269fc92f61098ee6bd635a0426129ce2c5456/lib/api/groups.rb#L17. The groups indexed in the web form will only be those groups that the user is currently a member of.

The new implementation allows projects to be shared with any group that the authenticated user has access to view. This widens the range of groups to those that are public and internal.

See merge request !2005
Signed-off-by: Rémy Coutable <remy@rymai.me>

From 8.15s to 4.55s by grouping expectations
Signed-off-by: Rémy Coutable <remy@rymai.me>

This commit adds a number of _html columns and, with the exception of Note,
starts updating them whenever the content of their partner fields changes.

Note has a collision with the note_html attr_accessor; that will be fixed later

A background worker for clearing these cache columns is also introduced - use
`rake cache:clear` to set it off. You can clear the database or Redis caches
separately by running `rake cache:clear:db` or `rake cache:clear:redis`,
respectively.

FIxes #19361, #3119.

Allow to set request_access_enabled for groups and projects using API

Closes #20978

See merge request !6359

Also, fix the failing test in the process

Also, in favour of consistency, deprecate `/projects/:id/keys/...` routes in favour of
`/projects/:id/deploy_keys/...`

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