disable ability to regrade a question if they change the question type

fixes CNVS-10868

test plan:
  - as a teacher
    - create a quiz with both multiple choice and multiple fill in the
      blank questions
    - publish the quiz

  - as a student
    - take the quiz

  - as a teacher
    1:
    - attempt to change the answer for the multiple choice question
    - regrade should be successful
    - view the results for the student's quiz - the answer should be regraded
      successfully

    2:
    - attempt to change the answer for the multiple fill in the blank
    - there shouldn't be an option to regrade
    - attempt to change the question type for the mfiib question to be a
      multiple choice question.
    - now try to change the answer
    - it should show you a message that regrade is disabled because you
      changed the question type
    - view the results for the student's quiz - all answers should show up
      and regrade should not be performed on the question

    3:
    - attempt to remove a question from the multiple choice question
    - attempt to change the answer and regrade
    - it should show you a message that regrade is disabled because you
      removed answers
    - view the results for the student's quiz - all answers should show up
      and regrade should not be performed on the question

Change-Id: I50f15a0f1485bb6e152a90d9bb9eefcffe1bd2e1
Reviewed-on: https://gerrit.instructure.com/32469
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Stanley Stuart <stanley@instructure.com>
Reviewed-by: Josh Simpson <jsimpson@instructure.com>
QA-Review: Caleb Guanzon <cguanzon@instructure.com>
Product-Review: Derek DeVries <ddevries@instructure.com>