quizzes ember show page: dropdown menu

implements some dropdown menu functionality on the quiz show page.

Test plan:
  In the quizzes dropdown menu on the show page:
  - Speedgrader link should take you to speedgrader
  - Lock/Unlock the quiz should work correctly
  - Delete should work correctly

closes CNVS-11792

Change-Id: Id71672f58111784fa1c321519f777e9ca605e46c
Reviewed-on: https://gerrit.instructure.com/30464
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jason Madsen <jmadsen@instructure.com>
QA-Review: Caleb Guanzon <cguanzon@instructure.com>
Product-Review: Stanley Stuart <stanley@instructure.com>