Make it possible to correct an acception or rejection in registrations

One-sentence description

Make it possible to correct an acception or rejection

Desired behaviour

Accepted or rejected registration can only be deleted but not corrected or changed in any way. We should make it possible to correct this. For example if it was a mistake or if the payment object was not created.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information