R1:179d80dd57f8

Migrate Project lock to modular transactions

Summary: See T12673

Test Plan: Unit tests pass. Locked and unlocked a project and saw timeline changes.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D17986