Backend to make templates private or public (S)

[pieperm]

Definition of Done

• New column on feedback template that determines whether a template is private or public
• A private template can only be used/seen by the template creator and admins
• Consequently, only members who have access to a private template can use that template when creating a feedback request
• A public template can be used by any authenticated member
• Database migration
• Adjust testing data to include examples of both private and public templates
• Integration tests