use all paginated quizzes in ember index

closes CNVS-13628

test plan:
  - enable :quiz_stats
  - visit quiz index with more than 20 quizzes
    - verify that first 10 load
      - loading spinner will display at bottom of first 10 records
    - remaining quizzes should then load and display
      - spinner will remove once all pages are loaded

  - visitin quiz index with less than 10 quizzes
    - bottom spinner should not be visible

Change-Id: Ie2d6989b6ad68782d50c0491cd0fd3a761976577
Reviewed-on: https://gerrit.instructure.com/36437
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Derek DeVries <ddevries@instructure.com>
QA-Review: Caleb Guanzon <cguanzon@instructure.com>
Product-Review: Jason Madsen <jmadsen@instructure.com>