R1:774fba3ce925

Migrate Project workboard to modular transactions

Summary: This was interesting, because there were a mix of callsites using transactions and others that just set the property on the `Project` object. I made everything consistent in using transactions to change this property. I also found an implementation of `getTitle()` that I don't think is ever being invoked since `shouldHide()` is returning `true`, but I migrated it anyway.

Test Plan: Unit tests pass + enabling/disabling workboards (and importing).