Enable QR code display by default in otptoken-add
    
    This is possible because python-qrcode's output now fits in a standard
    terminal. Also, update ipa-otp-import and otptoken-add-yubikey to
    disable QR code output as it doesn't make sense in these contexts.
    
    https://fedorahosted.org/freeipa/ticket/4703
    
    Reviewed-By: Petr Vobornik <pvoborni@redhat.com>