KKamaa

Final test on it see attached: 

@OCA/community-maintainers could someone give a check on this

> @KKamaa I rebased on #529 in [this branch](https://github.com/OCA/delivery-carrier/compare/14.0...sunflowerit:delivery-carrier:14.0-mig-base_delivery_carrier_files_document?expand=1) whilst keeping your code the same, could you use that and force-push over here? Then I'll review the migration commit @thomaspaulb...

Should be ok. I added it a while back, did you test?

> @KKamaa What's the status of this ? Should be ok, maybe a rebase is required.