Display users' status messages on the user handle in markdown

Problem to solve

Users are mentioned in several places across GitLab which might mean that they've been effectively ping-ed when, in fact, they're OOO for 2 weeks.

Intended users

Everyone who uses: Issues, Epics, MRs and also gets involved in discussions anywhere.

Further details

This will prevent communication breakdown and expectation failures by improving visibility of users' availability.

Proposal

Which on hover will display the popover, which will clarify what the user status is.

What does success look like, and how can we measure that?

A good scenario to test is when pinging users for QA issues, which have a very short deadline, we can clearly see which are the users that might not be available in time by checking usernames with emojis in front.

Links / references