Add setting to allow/restrict having questions of type 'file upload'

[binford6000]

Nextcloud (please complete the following information):

• Nextcloud-Version: [31.0.0.14]
• Forms-Version: [4.3.6]

Is your feature request related to a problem? Please describe. In high security environments - eg. a bank - admins won't allow to have file uploads in forms.

Describe the solution you'd like There should be an admin setting allowing or restricting questions of the type file upload. Allow: Users are allowed to add questions of type file upload Restrict: Users won't have that type of question

Additional context Additionally there should be a hint when set to allowed, that admins should consider to take further actions (Antivirus for files or file access control) to deal with this potential threat.