make SRs reread buttons when moving help links
make SRs reread buttons when moving help links

SRs would only reread the buttons if the focus changed, and react makes
sure the DOM elements don't change, so the focus wasn't changing and SRs
just did what they're supposed to do. So we have to trick them by
changing the focus and then changing it back.

fixes CNVS-36606

test plan:
* move help links up and make sure the up button gets read again
  * NVDA will read the edit button and then the up button, which is
  * better than reading nothing
* ditto with the delete button

Change-Id: I946cba90f8ba252934a23fc9d5f4117bb1081919
Reviewed-on: https://gerrit.instructure.com/124298
Tested-by: Jenkins
Reviewed-by: Venk Natarajan <f9eab59b292314637a3c917fea4742741e36a19b@instructure.com>
QA-Review: Deepeeca Soundarrajan <5bcd4b623f00b7fc2942cd1c65c245b30a48a61f@instructure.com>
Product-Review: Jon Willesen <0321efbc0acf6204eb6035acb1d418838b450d08@instructure.com>

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