Print label and print certificate shouldn't be available before saving an appointment when creating the appointment

We can print label before saving when creating an appointment.

Issue: some secretaries click on "print label" and then close the appointment-creation pop-up without saving because they have the label in hand.

To prevent issues, "print label" and "print certificate" shouldn't be available (visible, but disabled) when the appointment hasn't been created officially (saved for the 1st time)