Achievement badges on user photos in plog lists

Provide a way for users to show off their achievements publicly.

In the plog lists (both History and Local)*, add a small achievement badge to the user's photo. Ideally each achievement will have an badge that is visually distinct, and the badges will be small enough so that 3-4 can be displayed without obscuring the underlying photo.

For example, if a user unlocks Danger Pay, overlay a small hard hat on the bottom right corner of their user photo.

Currently, there is no way for users to view each other's profiles, so this would provide a way to show off your achievements, and also what others near you have unlocked.

*These wouldn't necessarily need to be displayed in the history feed, but doing so would provide consistency between the two feeds.