WIP: Persist performance metrics for a Merge Request within GitLab

What does this MR do?

Stores Prometheus metrics in stored_metrics table that the can be used to access them later

Why was this MR needed?

Prometheus removes metrics after some (configurable) time. Additionally Prometheus is not recommended as long term storage for metrics. Thus to be able to reliably access data used for 'Spark Line' metrics in merge request we need to store them in the database.

Storing is performed by dedicated worker that is scheduled to runes 30 minutes after deployment is created.

This MR is based on !9950 (closed) and before that MR is merged to master. This MR will also contain the code.

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?

Closes #27545 (moved)