Support additional prometheus metrics - review branch

What does this MR do?

This MR contains all the changes necessary for adding support for additional Prometheus metrics. Including UI changes which has been reviewed in separate MR's

Only backend changes need to be reviewed here.

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

Backend

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 #28717 (closed)