Makes new student groups accessible

Fixes: CNVS-13350

The new groups page was not accessible. Specifically
the keystrokes were not expanding the group details.
Groups can now be expanded via the keyboard and
focus is explicitly set afterwards in order to
make the screenreader read the expansion.

Test-Plan:
1.) Create a group and add a user to it
2.) Masquerade as user
3.) Navigate to new groups page
4.) Turn on screen-reader
5.) Navigate using keyboard to the group-name
    and verify that it expands and reads the details

Change-Id: I3fe5c62e59e2f7d3053af46685c57f40dcf33d00
Reviewed-on: https://gerrit.instructure.com/37379
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Matthew Wheeler <mwheeler@instructure.com>
Product-Review: Matthew Wheeler <mwheeler@instructure.com>
Tested-by: Matthew Wheeler <mwheeler@instructure.com>
QA-Review: Steven Shepherd <sshepherd@instructure.com>