manage focus after closing context card message dialog
manage focus after closing context card message dialog

fixes FALCOR-66

Test plan:
  - open the student context tray
  - open the message-student dialog
  - using the keyboard, close the message-student dialog
  - focus should be returned to the message link

Change-Id: I5a45c7baad9ebf672a46e43963a974955e68cfeb
Reviewed-on: https://gerrit.instructure.com/99950
Tested-by: Jenkins
Reviewed-by: John Corrigan <3d73713d0cc718326e4fd7c06c64e067ad6e2270@instructure.com>
QA-Review: Dan Sasaki
Product-Review: Dan Sasaki

SwinburneOnline/canvas-lms,grahamb/canvas-lms,SwinburneOnline/canvas-lms,venturehive/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,grahamb/canvas-lms