Order only for latest_successful_for

See merge request !8301

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/8286#note_20461082

This reverts merge request !8286

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/8286/diffs#note_20433402

The name latest implies that it's reverse chronological,
and we did expect it that way.

https://gitlab.com/gitlab-org/gitlab-ce/issues/25993#note_20429761

>>>
ok, I think markglenfletchera is correct in
https://gitlab.com/gitlab-com/support-forum/issues/1394#note_20399939
that `Project#latest_successful_builds_for` is giving oldest pipeline
rather than latest pipeline. This is a ~regression introduced by !7333
where `order(id: :desc)` was removed causing this. The offending change
was:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7333/diffs#b22732e5f39e176c7c719fe485847d0fb0564275_92_108

The confusion was caused by the `latest` name implication, which
actually didn't order anything, and I think we should add `order(id:
:desc)` to `Ci::Pipeline.latest` otherwise it's confusing that it's not
actually ordered.
>>>

Closes #25993

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.

[ci skip]