Ember Quiz Stats - Pre-activate answer set

FIMB, Matching, and Multiple-Dropdown question statistics should now
have the first answer-set pre-activated for you as soon as you visit the
stats page.

Closes CNVS-13614

TEST PLAN
---- ----

  - enable NQS
  - create a quiz with those question types
    + take it by one student for the stats to show
  - visit the stats page
    + verify that the question statistics sections for those question
      types have the first answer-set activated and the details expanded
    + verify you can still activate other sets
  - verify the page doesn't break with questions that have 0 sets

CR NOTES
-- -----

  - ajax fixture was outdated and causing jenkins to fail which is why
    the integration spec was modified

Change-Id: I46872f17ec267eaf7e8c32a32715a984f0ce3750
Reviewed-on: https://gerrit.instructure.com/38341
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jason Madsen <jmadsen@instructure.com>
QA-Review: Caleb Guanzon <cguanzon@instructure.com>
Product-Review: Ahmad Amireh <ahmad@instructure.com>