* Return a template response for displaying the editor
*
* open can only be called once when the client requests the editor with a one-time-use token
* For handling editing and later requests, editors need to impelement their own token handling and take care of invalidation
* For handling editing and later requests, editors need to implement their own token handling and take care of invalidation
*
* This behavior is similar to the current direct editing implementation in collabora where we generate a one-time token and switch over to the regular wopi token for the actual editing/saving process