Bug 25812: Fines can be displayed on SIP checkin/checkout

Bug 25812: Fines can be displayed on SIP checkin/checkout

Test plan:

 - Enable show_outstanding_amount in SIPconfig.xml

 - Check that the total outstanding amout for the patron is displayed on SIP
   checkout (if it exists), for example:
   Patron has fines - You owe $10.00.

 - Check that the outstanding amout for a given item is displayed on SIP
   checkin (if it exists), for example:
   "You owe $10.00 for this item."

 - Check that it is not displayed when show_outstanding_amount is disabled.

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>