Mostly use PhrictionContentQuery to load PhrictionContent objects
Summary: Depends on D19094. Ref T13077. Use modern infrastructure to perform these loads. I left a couple of calls in the older API methods unconverted.
Test Plan: Viewed documents. Viewed older versions. Viewed diffs. Did revert edits to older versions.
Maniphest Tasks: T13077
Differential Revision: https://secure.phabricator.com/D19095