Summary: Ref T2222. Ref T3886. Differential has a legacy storage table for auxiliary fields; move the data to modern storage.
Test Plan:
- Ran migration.
- Verified fields still worked properly afterward (view, edit, etc).
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T3886, T2222
Differential Revision: https://secure.phabricator.com/D8355
