EE Version of 9-2-5 Master security update

What does this MR do?

This is the EE counterpart to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12025

With the included test fix from https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/2078

This MR, in addition to https://gitlab.com/gitlab-org/gitlab-ee/commit/df0b99e25efbb53cd1d43915ad1c6002f1f9fd5e

should represent the entire 9.2.5 security fixes

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

Why was this MR needed?

Screenshots (if relevant)

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

What are the relevant issue numbers?