DA - quiz/submission/discussion notifications

fixes CNVS-15156

test plan:
  - with DA on:
    - submission:
      - make a differentiated assignment
      - turn in a submission as a student
      - give the student a grade
        - as the student, ensure you have the notification, and then
          delete it
      - as a teacher, take away visibility and delete their grade
        - as the student, you should not have a new notification for grade
          changing
      - as a teacher, comment on this submission
        - as the student, you get notified about the comment
    - quiz:
      - as a teacher make a differentiated quiz
        - students without visibility dont get notified about it
    - discussion:
      - discussion notifications are broken so we cant QA
  - with DA off:
    - submission:
      - comment on a submission as a teacher and make sure the
        student is notified
      - grade a student as a teacher and make sure the student
        is notified
    - quiz:
      - making & assignment a quiz sends out notifications properly
    - discussion:
      - discussion notifications are broken so we cant QA

Change-Id: I891f9782b5ae70252e7949a6858896b73ac28871
Reviewed-on: https://gerrit.instructure.com/41025
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cameron Sutter <csutter@instructure.com>
QA-Review: Sean Lewis <slewis@instructure.com>
Product-Review: Hilary Scharton <hilary@instructure.com>