force links to _top to avoid inception bug

closes CNVS-3089

test plan:
  - as a teacher, create a quiz that can be taken multiple times
  - as a student, take the quiz and submit
  - as a student, go to |Home| > |Recent Feedback|
    - click on the quiz that was just taken
    - click links (including 'Take the Quiz Again')
      - verify that page re-loads correctly
      - verify that a new sub-instance of canvas is not loaded

Change-Id: I6559103fddd1a4ca6820e079d0c6973c27086433
Reviewed-on: https://gerrit.instructure.com/32793
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Myller de Araujo <myller@instructure.com>
Reviewed-by: Derek DeVries <ddevries@instructure.com>
Product-Review: Jason Madsen <jmadsen@instructure.com>