Remove extra "next" and "previous" messages for screen readers
Remove extra "next" and "previous" messages for screen readers

fixes CNVS-25450
fixes CNVS-25444

test plan:
- Take a OQAAT Quiz
- Ensure that the next and previous buttons are only read once
- Test on all screen reader combonations
  (note: in NVDA ensure that pressing down doesnt repeat the next
  or previous message.)

Change-Id: I49ae2adde4251b848196cfe4142097785a336091
Reviewed-on: https://gerrit.instructure.com/70048
Tested-by: Jenkins
Reviewed-by: Matt Berns <e53c8988cd428dde240324ce2797c8eb7073560f@instructure.com>
QA-Review: Michael Hargiss <59e3fde81b8d9a4f5e0cc016a3c2695591912604@instructure.com>
Product-Review: Aaron Cannon <25919c673621c006b735dcd5a28df63325948e2b@instructure.com>

SwinburneOnline/canvas-lms,HotChalk/canvas-lms,SwinburneOnline/canvas-lms,redconfetti/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,dgynn/canvas-lms,venturehive/canvas-lms,venturehive/canvas-lms,redconfetti/canvas-lms,fronteerio/canvas-lms,instructure/canvas-lms,matematikk-mooc/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,grahamb/canvas-lms,dgynn/canvas-lms,fronteerio/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,matematikk-mooc/canvas-lms,roxolan/canvas-lms,roxolan/canvas-lms,instructure/canvas-lms,HotChalk/canvas-lms,instructure/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,fronteerio/canvas-lms,djbender/canvas-lms,fronteerio/canvas-lms,grahamb/canvas-lms,SwinburneOnline/canvas-lms,HotChalk/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,dgynn/canvas-lms,sfu/canvas-lms,dgynn/canvas-lms,roxolan/canvas-lms,grahamb/canvas-lms,roxolan/canvas-lms,redconfetti/canvas-lms,instructure/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,redconfetti/canvas-lms,matematikk-mooc/canvas-lms,matematikk-mooc/canvas-lms,HotChalk/canvas-lms,venturehive/canvas-lms,djbender/canvas-lms