R1:48a74de0b649

Move all revision status transactions to modern values and mechanics

Summary:
Ref T2543. This updates and migrates the status change transactions:

- All storage now records the modern modular transaction ("differential.revision.status"), not the obsolete non-modular transaction ("differential:status").
- All storage now records the modern constants ("accepted"), not the obsolete numeric values ("2").

Test Plan:
- Selected all the relevant rows before/after migration, data looked sane.
- Browsed…