Assigned editorial comments do not show notifications

[mikelittle]

Assigning editorial comments to as user do not show the notifications they are supposed to.

Steps to reproduce: Following the instructions in the testing ticket:

1. Add an editorial comment on a post and assign your current user
2. Check that the notification appears in the admin bar and that the action links work
3. See the notifications do not appear.

Notification count should reflect the number of comments assigned.

Acceptance criteria:

• [ ] ...