R1:4250719d1008

Destroy notifications properly from `bin/remove destroy`

Summary: Fixes T8237. This table is unusual and doesn't have an `id` column, so `delete()` doesn't actually know how to delete records and fails.

Test Plan:
- Used `bin/remove destroy` to destroy an object with notifications, as per T8237.
- Applied patch.
- Used `bin/remove destroy` to get a clean delete.
- Verified related notifications vanished from notification menu.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley…