Action when departments which no staff are clicked

Changed the getFacultyNames() method to retrieve the names from the room
table so that even empty rooms are displayed. So from henceforth,
description column in office table is the name of the room (Co-Op, Guild
Office etc.)
Edited the getFacultyStaffsIdsNames() method to return an empty list if
there are no staffs in that faculty

Clicking on departments with no staff now advances to the StaffActivity
page immediately