R1:e7ebd5d9d1f8

Make "Delete" from inline comment previews function correctly while editing comments

Summary: Ref T13513. Currently, if you're editing a comment, "delete" doesn't put the comment into the correct state. This action is normally only reachable from comment previews, since an editing inline has no "delete" button.

Test Plan:
- Started editing an inline, clicked "Delete", got a deletion.
- Created an inline, typed text,
- Deleted a normal comment via preview.
- Deleted a normal comment via the on…