Revert "Merge branch 'revert-82d7b5a0-ce' into 'master'"

CE port of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9704. This replaces https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25547.

What does this MR do?

This cherry-picks 3 merge commits that were reverted by https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25537:

• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25416 => 4b282e9c
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/24960 => d133bf84 + a fix (c00354a4).
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25517 => 9202bbd1

Note: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25201 isn't cherry-picked since it introduces a N+1 queries problem in EE (https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9704#note_145071430).

CE port of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9704, please see the additional fixes https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9704#fixes

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Security reports checked/validated by reviewer