Make new EditEngine Audit transactions apply old mail tags

Summary: Ref T10978. Until T10448 makes mail tags modular, keep the old tags working.

Test Plan: Made some commit edits, ran bin/phd debug task to process mail for them.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10978

Differential Revision: https://secure.phabricator.com/D17190