Migrate Pholio inline comments to modular transactions

Summary: Fixes T12626.

Test Plan: Made lots of comments, confirmed no UI changes

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley

Maniphest Tasks: T12626

Differential Revision: https://secure.phabricator.com/D17914