calendar2: update mini calendar with changes

fixes CNVS-10817

test plan:
  * load calendar2
  * create an event
  * verify that the day is darkened in the mini calendar
  * reschedule the event
  * verify that the mini calendar updates
  * delete the event
  * verify that the mini calendar updates

Change-Id: Ib3bffd866d2fb825af6804dc22ab1a92e93fb0b8
Reviewed-on: https://gerrit.instructure.com/31603
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Steven Shepherd <sshepherd@instructure.com>
Reviewed-by: Jon Willesen <jonw@instructure.com>
Product-Review: Braden Anderson <banderson@instructure.com>