Having possibility to define detected ports by model importer as OPTIONAL ports

[farshbafdoustar]

Is your feature request related to a problem? Please describe.
current model importer detects all ports in the xml node and tries to check the next occurrences with the same PortList assuming all the ports are necessary to be presented again.

Describe the solution you'd like
Being able to mark a checkbox beside the port name or type to set it as optional port.