Bug 18259: Koha::Biblio - Remove GetSubscriptionsId

Bug 18259: Koha::Biblio - Remove GetSubscriptionsId

C4::Biblio::GetSubscriptionsId can be replaced using
Koha::Biblio->subscriptions

Test plan:
Create a new order for a bibliographic record
Create a new subscription on this biblio
From the basket (acquisition), confirm that you are not able to delete
the order with the biblio ("Can't cancel order and delete catalog record
1 subscription(s) left")
Receive the order
On the parcel page, confirm that you are not able to delete the order
with the biblio

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>