Add colored status icons

Problem to solve

The status icons (merged, closed, etc.) could be colored, as shown here: gitlab-foss#25899 (comment 20590484).

Intended users

User experience goal

Proposal

Further details

Permissions and Security

Documentation

Availability & Testing

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

What is the type of buyer?

Is this a cross-stage feature?

Links / references