adjust styles for ember quizzes#show overview and add styles for moderate page

fixes CNVS-12439, CNVS-12446

test plan:
  - turn on fabulous quizzes
  - visit an individual quiz
  - on the overview tab
    - the styles should more closely match the original design

  - on the moderate tab
    - there should be a styled moderate table

Change-Id: I8fc6782ef1f73f59840648ddbe48a15d1e16547c
Reviewed-on: https://gerrit.instructure.com/33685
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Caleb Guanzon <cguanzon@instructure.com>
Reviewed-by: Josh Simpson <jsimpson@instructure.com>
Product-Review: Derek DeVries <ddevries@instructure.com>