Bug 34820: Clarify inventory tool message for items with non-matching notforloan...

Bug 34820: Clarify inventory tool message for items with non-matching notforloan value

In the inventory tool, if one or more not for loan values are selected, and an item is scanned that has no NFL status or an unselected NFL status, the error message reads "Unknown not-for-loan status". This can be interpreted as the item having an NFL status value that is not defined in the system, but that is not accurate. This should be reworded to remove ambiguity.

Test plan:
1) Create two items, one of which has the NFL status of "Ordered", the
   other having no NFL status
2) Enter those two barcodes in the inventory tool barcodes list
3) Check only "Ordered" in items.notforloan
4) Note the problem messages
5) Apply this patch
6) Re-run the inventory tool
7) Note the new clarified messages!

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>