Bug 22437: (follow-up) Move deletion of merge requests to DelAuthority

Bug 22437: (follow-up) Move deletion of merge requests to DelAuthority

Lines can be moved. Deletion can be done too if skip_merge is not set.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Joy Nelson <joy@bywatersolutions.com>
(cherry picked from commit 2cb01116ee3ed6ce6296cb0ad5e794fd68e58f8a)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>