Bug 21150: Search for item types inconsistencies

Bug 21150: Search for item types inconsistencies

search_for_data_inconsistencies.pl will now display errors if:
1.item-level_itypes is set to "specific item" and items.itype is not set
or not set to an item type defined in the system (itemtypes.itemtype)
2.item-level_itypes is set to "biblio record" and biblioitems.itemtype is not set
or not set to an item type defined in the system (itemtypes.itemtype)

Test plan:
Use the script and the different possible combinations to display the
errors

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>