speed up views/quizzes/_display_question.html.erb rendering
speed up views/quizzes/_display_question.html.erb rendering

Fixes #11973

Previously, QuizzesHelper.answer_type returned an OpenObject, which when
used in quizzes/_display_question.html.erb and subsequent partials,
caused a slowdown.

Test Plan:
  - Check out master and start a server.
  - If you don't have a quiz, create one.
  - Try to edit the quiz by using the "Edit this Quiz" button.
  - Watch the render times for display_question.html.erb and record the
    render times.
    - script/server | grep 'display_question.html.erb' is useful.
  - Repeat by refreshing the page a few times so you get a good sample
    size ( 5 or 6 times is good enough )
  - Check out this commit
  - Watch the render times again like you did previously for master
  - Render times on this commit should be faster than master.
  - You should be able to edit the quiz as usual.

Change-Id: I2ab080c80ab233e7b5fe6773f9f2c033e4dfcbad
Reviewed-on: https://gerrit.instructure.com/15663
Reviewed-by: Cody Cutrer <c4fe2b1d90ef8f2548c8aeabfa633434316f0305@instructure.com>
Reviewed-by: Jacob Fugal <f862f167b85d41b225785c70d70808bc7337c1fe@instructure.com>
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Amber Taniuchi <ef4bfd1e6d278f6bc7d4a478f02be2cb9581a0a5@instructure.com>

sfu/canvas-lms,greyhwndz/canvas-lms,Rvor/canvas-lms,Jyaasa/canvas-lms,instructure/canvas-lms,roxolan/canvas-lms,sfu/canvas-lms,tgroshon/canvas-lms,landonwilkins/canvas-lms,leftplusrightllc/canvas-lms,wrdsb/canvas-lms,va7map/canvas-lms,narigone/canvas,efrj/canvas-lms,narigone/canvas,juoni/canvas-lms,grahamb/canvas-lms,redconfetti/canvas-lms,matematikk-mooc/canvas-lms,snehakachroo1/LSI_replica,arrivu/hiring-site,fronteerio/canvas-lms,jay3126/canvas-lms,shidao-fm/canvas-lms,sfu/canvas-lms,grahamb/canvas-lms,instructure/canvas-lms,samuels410/greatlakes-lms,utkarshx/canvas-lms,snehakachroo1/LSI_replica,wye0220/shindig-canvas,instructure/canvas-lms,arrivu/arrivu-lms,SwinburneOnline/canvas-lms,HotChalk/canvas-lms,sfu/canvas-lms,va7map/canvas-lms,gbleydon/canvas-lms,redconfetti/canvas-lms,venturehive/canvas-lms,arrivu/qibla-ecampus,sdeleon28/canvas-lms,wye0220/shindig-canvas,Rvor/canvas-lms,Jyaasa/canvas-lms,Jyaasa/canvas-lms,skmezanul/canvas-lms,HotChalk/canvas-lms,usmschuck/canvas,sli7246/canvas_branch,fronteerio/canvas-lms,grahamb/canvas-lms,skmezanul/canvas-lms,instructure/canvas-lms,landonwilkins/canvas-lms,sli7246/canvas_branch,ShreniiNepal/shrenii_lmp,arrivu/qibla-ecampus,eCNAP/CANVAS,roxolan/canvas-lms,whalejasmine/canvas-lms,shidao-fm/canvas-lms,samuels410/greatlakes-lms,dgynn/canvas-lms,eCNAP/CANVAS,wimemx/Canvas,djbender/canvas-lms,HotChalk/canvas-lms,sdeleon28/canvas-lms,leftplusrightllc/canvas-lms,tgroshon/canvas-lms,tgroshon/canvas-lms,arrivu/jigsaw-lms,sdeleon28/canvas-lms,jay3126/canvas-lms,instructure/canvas-lms,utkarshx/canvas-lms,rup/Tarrax,juoni/canvas-lms,AndranikMarkosyan/lms,parbros/red-innovadores-lms,shidao-fm/canvas-lms,dgynn/canvas-lms,djbender/canvas-lms,usmschuck/canvas,instructure/canvas-lms,antoniuslin/canvas-lms,jay3126/canvas-lms,whalejasmine/canvas-lms,Jyaasa/canvas-lms,wimemx/Canvas,landonwilkins/canvas-lms,shidao-fm/canvas-lms,antoniuslin/canvas-lms,narigone/canvas,efrj/canvas-lms,SwinburneOnline/canvas-lms,arrivu/hoodemo,Unow/canvas-lms,rup/Tarrax,whalejasmine/canvas-lms,utkarshx/canvas-lms,rup/Tarrax,greyhwndz/canvas-lms,juoni/canvas-lms,nditech/red-innovadores-lms,arrivu/jigsaw-lms,eCNAP/CANVAS,kyroskoh/canvas-lms,kyroskoh/canvas-lms,loganrun/pincan,SwinburneOnline/canvas-lms,landonwilkins/canvas-lms,arrivu/hiring-site,eCNAP/CANVAS,arrivu/qibla-ecampus,ShreniiNepal/shrenii_lmp,roxolan/canvas-lms,va7map/canvas-lms,gbleydon/canvas-lms,merichar/canvas-lms,sfu/canvas-lms,ShreniiNepal/shrenii_lmp,efrj/canvas-lms,parbros/red-innovadores-lms,grahamb/canvas-lms,AndranikMarkosyan/lms,merichar/canvas-lms,va7map/canvas-lms,Unow/canvas-lms,efrj/canvas-lms,merichar/canvas-lms,utkarshx/canvas-lms,venturehive/canvas-lms,dgynn/canvas-lms,sdeleon28/canvas-lms,wrdsb/canvas-lms,redconfetti/canvas-lms,nditech/red-innovadores-lms,loganrun/pincan,jay3126/canvas-lms,kyroskoh/canvas-lms,ShreniiNepal/shrenii_lmp,wrdsb/canvas-lms,greyhwndz/canvas-lms,arrivu/hoodemo,parbros/red-innovadores-lms,arrivu/arrivu-lms,Rvor/canvas-lms,Unow/ins,usmschuck/canvas,tgroshon/canvas-lms,fronteerio/canvas-lms,roxolan/canvas-lms,grahamb/canvas-lms,arrivu/hoodemo,sli7246/canvas_branch,fronteerio/canvas-lms,instructure/canvas-lms,Unow/canvas-lms,redconfetti/canvas-lms,gbleydon/canvas-lms,whalejasmine/canvas-lms,samuels410/greatlakes-lms,leftplusrightllc/canvas-lms,wye0220/shindig-canvas,antoniuslin/canvas-lms,venturehive/canvas-lms,matematikk-mooc/canvas-lms,sfu/canvas-lms,snehakachroo1/LSI_replica,sfu/canvas-lms,wimemx/Canvas,arrivu/arrivu-lms,usmschuck/canvas,antoniuslin/canvas-lms,nditech/red-innovadores-lms,venturehive/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,matematikk-mooc/canvas-lms,dgynn/canvas-lms,narigone/canvas,kyroskoh/canvas-lms,SwinburneOnline/canvas-lms,samuels410/greatlakes-lms,leftplusrightllc/canvas-lms,Unow/ins,greyhwndz/canvas-lms,loganrun/pincan,skmezanul/canvas-lms,wrdsb/canvas-lms,arrivu/hiring-site,Rvor/canvas-lms,matematikk-mooc/canvas-lms,AndranikMarkosyan/lms,arrivu/jigsaw-lms,Unow/ins,snehakachroo1/LSI_replica,HotChalk/canvas-lms,AndranikMarkosyan/lms,juoni/canvas-lms,nditech/red-innovadores-lms,skmezanul/canvas-lms