Container repository cleanup API

What does this MR do?

This adds Container Registry manipulation API.

The most important part of this API is Tags cleaner. Tags cleaner offers a bunch of options to remove obsolete tags from the system:

1. The Tags Cleaner never touches :latest,
2. The Tags Cleaner only removes blobs matching name_regex,
3. The name_regex is a required parameter and has to be provided by the project owner,
4. If you want to match all tags you need to specify .* for name_regex,
5. You can always unconditionally keep n-latest images with keep-n,
6. You can specify older_than only tags older than given timespec will be removed,
7. The API schedules asynchronous job,
8. The job can be run no more than once per-hour (as this is a very expensive operation to walk all revisions),

Look at app/services/projects/container_repository/cleanup_tags_service.rb to understand the ordering of the operations as defined above.

Notice

Tags cleaner does not remove actual blobs. The blobs need to be removed separately using registry garbage-collect or docker-distribution-pruner.

What are the relevant issue numbers?

Resolves https://gitlab.com/gitlab-org/gitlab-ce/issues/55978

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer