[Redesign] Slight border inset on all profile photos
Summary: Ref T8099, Cleans up profile photos around the site in a more consistent way.
Test Plan: grep for 'background-size: 100%'
Reviewers: btrahan, epriestley
Reviewed By: epriestley
Subscribers: epriestley, Korvin
Maniphest Tasks: T8099
Differential Revision: https://secure.phabricator.com/D13360