WIP: Adjust position and wording for related issues in merge requests (second attempt)

What does this MR do?

• display related issues of a merge request above cherry pick and revert buttons
• uses past tense after merging (for example Closed issue instead of Closes issue)
• correctly pluralizes for three or more issues

Screenshots

TODO

What are the relevant issue numbers?

fixes #32809 (closed), #33652 (closed), #32641 (closed)

This is redoing the reverted !11759 (merged).