Publish AI review as a review
What does this MR do and why?
Instead of creating a note per reviewed hunk, we create draft notes in bulk and then publish it.
This is behind ai_review_merge_request
feature flag.
MR acceptance checklist
Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.
Related to #455203 (closed)