Add milestone issue/MR links to release block footer
What does this MR do?
Adds a footer to release blocks that links to issues and merge requests in the associated milestone(s) as described in #29020 (closed).
UX specs
When no milestones are associated, no footer will be rendered.
When a single milestone is associated:
When multiple milestones are associated, the footer text will change to:
View Issues for milestones 12.3, 12.4, 12.5. View Merge Requests for milestones 12.3, 12.4, 12.5.
(From this discussion: !15764 (comment 213567676))
Screenshots
Edited by Nathan Friend