This page takes a list of user ids, filters it using the admin's
institutions (if institutional admin), and displays the list.

The admin can then either download the list as a CSV file, or suspend,
delete or change the auth instance of all the users in the list at once.

Change-Id: I792fa29403a0b5f818dceff1d9aab9e9cbd42661
Signed-off-by: Richard Mansfield <richard.mansfield@catalyst.net.nz>