Bug 33791: Pass itemnumber to $hold->fill

Bug 33791: Pass itemnumber to $hold->fill

Test plan:

Without this patch:
Place next available level on some book for patron A.
Checkout this book directly to patron A.
Check old_reserves table for this reserve; does not have itemnumber.

With this patch:
Do the same.
In old_reserves the itemnumber should be saved.
Run again t/db_dependent/Koha/Hold.t. Should pass.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>