a11y: Fix for New Files folder content listing

It has come down to thrashing the DOM to fix this issue.
It has something to do with the handlerKey stuff or something
but thrashing works for now because ShowFolder likely will
need some serious refactoring to fix otherwise.

fixes CNVS-16457

Test Plan:
  - Load up Better File Browsing
  - Use Safari and VoiceOver and go to new files.
  - Navigate to the folder listing.
  - You should be able to navigate it with VO
  - Refresh the page.  The same behavior should occur.
  - Navigate into a subfolder. The same behavior should occur.

Change-Id: Ie32a3d942de68740bb02a13c85b5a72ec42e1dd4
Reviewed-on: https://gerrit.instructure.com/43632
Reviewed-by: Ryan Shaw <ryan@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Jahnavi Yetukuri <jyetukuri@instructure.com>
Product-Review: Cosme Salazar <cosme@instructure.com>