WIP: CE->EE merge for `9-2-stable-ee`

What does this MR do?

• Pick the merge commit resulting from merging:

  1. The last green commit of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1837
  2. The latest ee/master that was merged into ce_upstream prior to 1.

• Merge 9-2-stable to 9-2-stable-ee

  1. Resolve all conflicts with --ours
  2. We expect that https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1837 has fixed all relevant conflicts correctly, and so --ours should fix all conflicts the right way.

Are there points in the code the reviewer needs to double check?

• Any flaws in this strategy?

Why was this MR needed?

• 9-2-stable-ee needs to be up to date with CE.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together