Bug 23659: Add DefaultHoldPickupLocation system preference

Bug 23659: Add DefaultHoldPickupLocation system preference

On the staff side behaviour differs for default pickup location when placing a hold or
placing an overridden hold. Additionally, the behaviour has changed betwee master and stables

We should provide a consistent default, and allow the library to specify their choice

Note this only affects staff client as there is only a single dropdown on OPAC and it is not
tied to items

To test:
 1 - Apply patch
 2 - Update database
 3 - Find a record with items from various branches, and at least one with a different home/holding branch
 4 - Ensure there is an item that requires override to hold, and  AllowHoldPolicyOverride  is enabled
 4 - Attempt to place hold
 5 - Confirm all dropdowns default to logged in library
 6 - Set DefaultHoldPickupLocation to item's home branch
 7 - Refresh and confirm all dropdowns match item home library except biblio level hold - still logged in library
 8 - Set DefaultHoldPickupLocation to item's holding branch
 9 - Refresh and confirm defaults
10 - Mark one of the items holding library as 'not a pickup location' in Admin->Libraries
11 - Refresh and confirm dropdown is now empty for that item

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>