Bug 29760: Add patron category column to view_holdsqueue.tt

Bug 29760: Add patron category column to view_holdsqueue.tt

To test:
1. Have some holds and build the holds queue.
2. Go to view_holdsqueue.tt, there is no patron category column
3. Apply patch
4. Look again, there should now be a column for 'Patron category'
   showing both the caterory name and the category code.
5. Make sure you can sort and filter by this new column
6. Go to table settings and make sure you can properly hide this column
   and all other columns in the Holds queue.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>