Merge pull request 'OZG-5010,OZG-5397 trim empty strings to null' (#327) from...

Merge pull request 'OZG-5010,OZG-5397 trim empty strings to null' (#327) from OZG-5010-single-bescheid-attachment-wird-nicht-zurueckgeliefert into master

Reviewed-on: https://git.ozg-sh.de/ozgcloud-app/vorgang-manager/pulls/327


Reviewed-by: OZGCloud <ozgcloud@mgm-tp.com>