Render user display names in trophy messages

Review Request #9932 — Created May 11, 2018 and submitted — Latest diff uploaded

Information

Review Board
release-3.0.x
0146434...

Reviewers

Trophy message rendering has been reworked. Instead of a method that
every TrophyType subclass must implement, instead they must only add a
format string attribute. By default, the recipient's name is the only
provided parameter, but TrophyType.format_display_text can be
overridden to add extra context. All builtin trophies have been updated
to use this new behaviour.

Ran unit tests.