Bug 18403: Only display libraries from group in dropdown lists

Bug 18403: Only display libraries from group in dropdown lists

From where patrons it's about patrons, we do not want to display the libraries
from all the system, but only the ones from the group.

Test plan:
- See the overdues (circ/overdue.pl) and make sure you can only see overdues from
patrons part of your group (do not forget to test the CSV export).
- Search for patrons, the 'library' filters (headers and left side) should only
display libraries from your group
- Search for article request by patron's library: only the libraries from your
group should be displayed

Signed-off-by: Signed-off-by: Jon McGowan <jon.mcgowan@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>