Bug 20469: Add item status to staff article request form

Bug 20469: Add item status to staff article request form

The template checks if an item is checked out, on hold (waiting or
transit), not for loan. (Note: This can be extended in the future
in a general include as we have at opac side.)

Test plan:
[1] Place an article request on an item on loan. Verify status on form.
[2] Place an article request on a waiting item. Check status again.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
[EDIT] Simplified on 2020-07-27
Removed Koha::Item->is_waiting_or_transit.
Use Koha::Item->itemtype to check notforloan on itemtype level.
Adjusted commit message accordingly.

Additional test:
[3] Place an article request on a not for loan item. Check status.

NOTE: Not for loan is informational too. It does not say that this item
is not available for an article request. Depends on local situation.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>