Add UsageRightsSelectBox to WikiSidebar

For schools that have usage_rights_required,
this commit adds the UsageRightsSelectBox to
the WikiSidebar for when files are uploaded
from the files tab.

closes CNVS-17124

Test Plan:
* Enable "Usage Rights Required" feature flag
* Go to any course as a teacher or admin
* Go to the Pages section for that course
* Select a page to edit or create a new one
* On the WikiSidebar on the right, select
  the "files" tab
* Click "Upload a new file"
* A form should appear that contains a
  "Usage Right" select box that says
  "Choose usage rights...", along with a
  yellow warning below that says "If you do not
  select usage rights now, this file will be
  unpublished after it's uploaded."
* Choose a file from your computer to upload,
  then click the "Upload" button
* The file should be uploaded but unpublished
* Choose another file to upload using the same steps above,
  but this time select a usage right in the select box
  and a copyright message
* The yellow warning should disappear when a usage
  right is selected
* Upload the file; it should be published now

Change-Id: I5db6e9de794f8298082f79b955073c8307ed979b
Reviewed-on: https://gerrit.instructure.com/45331
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Clay Diffrient <cdiffrient@instructure.com>
QA-Review: Anna Koalenz <akoalenz@instructure.com>
Product-Review: Dan Minkevitch <dan@instructure.com>