[Settings] separate submission comments from annotations notifications

Problem statement:

I rely on assignment comments to give students timely feedback to their questions. I have them set to notify me immediately. However, in one class I've had to turn it to daily digest because I'm having students do peer review using annotations. After a couple of times receiving 20+ email notifications for a single student's annotations to a peer. So now my responses to actual student questions are slower, and I am less likely to be able to help them when they are working.

Proposed solution:

Separate annotation notifications from assignment comments. They are a separate thing entirely, and used in different ways. They should each have their own options.

User role(s):

instructor