Add/move project member role into popover

This is an actionable insight from the UX Department: MRs experience async critique research (insight).

What

In comments, a project member's role is shown on the right, far from the user's name and details.

Why

It's easy to assume that the project member's role is not important to see at all times. Also, being visually disconnected from the user's name and details, it makes it harder to understand the relationship and what “Maintainer” or “Developer” mean.

How

Consider adding the member's role to the popover that appears when hovering their name in comments (or moving the role to only appear in the popover).