New `Members::RequestAccessService`

Part of #21979 (closed).

Does this MR meet the acceptance criteria?

• 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 you do - rebase it please)
• Squashed related commits together

mentioned in issue #21979 (closed)

Added 1 commit:

• ac8c7a6a - Fix specs that requires an access request

Reassigned to @DouweM

Marked the task All builds are passing as completed

Added 238 commits:

• ac8c7a6a...f8bd9625 - 236 commits from branch master
• 3f08f806 - New Members::RequestAccessService
• bcb23026 - Fix specs that requires an access request

@DouweM or @rspeicher Could you review?

Added 47 commits:

• bcb23026...187dd50f - 45 commits from branch master
• 396eed44 - New Members::RequestAccessService
• 865c53aa - Fix specs that requires an access request

That's weird, I keep getting this failure on the CI only:

  1) Projects::HousekeepingService#increment! increments the pushes_since_gc counter
     Failure/Error:
       expect do
         subject.increment!
       end.to change { project.pushes_since_gc }.from(0).to(1)

       expected result to have initially been 0, but was 1
     # ./spec/services/projects/housekeeping_service_spec.rb:52:in `block (3 levels) in <top (required)>'

Added 8 commits:

• 865c53aa...7afee665 - 6 commits from branch master
• 07257bba - New Members::RequestAccessService
• 615e1cfd - Fix specs that requires an access request

Added 70 commits:

• 615e1cfd...c20e4267 - 68 commits from branch master
• 70a75db0 - New Members::RequestAccessService
• 4c055f96 - Fix specs that requires an access request

Added 1 commit:

• cd5ba66e - Re-add the AccessRequestable concern

Added 1 commit:

• b054b38a - Remove duplicate methods

@DouweM @rspeicher @smcgivern Could you pleas review? Thanks!

Because this is internal I think we should push to %8.13. WDYT?

@rspeicher I agree. I'll still find time to review this, but other 8.12 stuff takes priority right now!

Milestone changed to %8.13

@rspeicher Sure thing!

@rymai One note, rest LGTM.

Reassigned to @rymai