Bug 31128: Unit tests

Bug 31128: Unit tests

This patch adds unit tests for the new effective_not_for_loan_status
which I add to the items api responses in this patchset.

Test plan
1) Run the unit test without applying the next commit, it should fail
2) RUn the test again after applying the next commit, it should pass

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>