Bug 13891: DataTables server-side processing - patron cards

Bug 13891: DataTables server-side processing - patron cards

This third patch removes the previous way to search for patron cards users.

Test plan:
1/ Add items to a patron card batch (patroncards/edit-batch.pl?op=edit&element_id=X)
2/ Add 1+ patrons to the batch
3/ Confirm there is no regression

Tested together with other patches.
Signed-off-by: Marc Veron <veron@veron.ch>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>