Bug 33568: Separate holdings

Bug 33568: Separate holdings

This needs to be well tested!
Sysprefs SeparateHoldings and SeparateHoldingsBranch
As well as the "Lost items in staff interface" that can be defined at
patron's category level.

This patch is simply restoring the previous behaviour but I think we
could do better.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Laurence Rault <laurence.rault@biblibre.com>
Signed-off-by: Emily Lamancusa <emily.lamancusa@montgomerycountymd.gov>
Signed-off-by: Tomás Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>