Bug 19718: Show message if patron has existing holds on a title

Bug 19718: Show message if patron has existing holds on a title

To test:
 1 - Set a rule to allow multiple holds on a title
 2 - Place a single hold in the opac for a patron
 3 - Return to record and attempt place a second hold
 4 - Note there is no message but that you must match the type placed before (item or record level)
 5 - Don't place the hold
 6 - Apply patch
 7 - Attempt to place second hold again
 8 - Note there is a message informing you of which level hold you may place
 9 - Test with both item/record level holds and placing a single request or multiple requests

Signed-off-by: Donna Bachowski <donna@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>