Provide the Option to edit form by sharing with a user or group

[timmwille]

Nextcloud (please complete the following information):

• Nextcloud-Version: latest stable
• Forms-Version: latest stable

Is your feature request related to a problem? Please describe.
For a lot of situations a form has to be designed and managed by multiple users/a working-group.

Describe the solution you'd like
Would be great to have a sharing option that allows also editing of the form

Describe alternatives you've considered
currently one has to setup a dummy account to manage the forms (sharing the access to results from there is possible, thank you for that, it already helps a lot).

Additional context
Might be added together with #617 #1945 - i could not find a matching issue, but might have overlooked, please link if I created a duplicate

[Chartman123]

Duplicate of #322