Bug 14805: Allow the user to delete multiple batches

Bug 14805: Allow the user to delete multiple batches

Allows the user to delete multiple patron card batches.

Test plan:

1. Add first some 20 batches
2. Go to the edit page of some X batch by first selecting from the
   batch list the batch you want to edit and then after that by clicking
   edit.
3. Delete one batch by selecting one batch and then clicking delete.
4. Select 0 batches and click delete, notice you cannot delete.
5. Select 0 batches and click edit, notice you cannot edit.
6. Select 2 batches and click edit, notice you cannot edit.
7. Apply patch
8. Check that steps from 2-6 work like they worked before.
   (and add more batches so that you have ~20 of them)
9. Select 2 batches and click delete. Make sure they are deleted.
10. Try to figure out some anomalies this patch might have caused.

Sponsored-by: Vaara-kirjastot
Followed test plan, works as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>