Assigns a User and User Type to an Appointment.
The ID of the Appointment to assign the User and User type to.
The ID of the User to be assigned.
The User type (0 - User, 1 - Outsource).
FM_api('Appointment_setUserIdAndType', ['id' => '139', 'user_id' => '82878', 'user_type' => '1'])
If the user id and user type are the same as the current {"ok":1,"warning":"no update necessary"}
If the Appointment id entered does not exist {"error":"no such appointment exists"}
