Bug 35574: Add unit tests for api change

Bug 35574: Add unit tests for api change

We add the corresponding unit tests for the biblio/bookings endpoint to
ensure no regressions in the future.

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 8bffe42f6be72504a68bc06c0a5f8e42a4e0aed3)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>