Notification Wish List *please don't merge*

I'm holding myself accountable by planning features prior to writing them. Here is what I would like to see in notification behavior. Please feel free to add more.  Related to #269 

- [ ] Clump by user's assignment
- [ ] Go to user's assignment and mark all read in one click
- [ ] mark all as read in one click without navigating there
- [ ] It should be visually apparent when the user's assignment is ongoing
- [ ]  /(un)subscribe to a submission
- [ ]  /(un)subscribe to a user's assignment
- [ ]  /(un)subscribe to a user