Intoduce process parameters callout minimal functionality

[teosarca]

Is this a bug or feature request?

FR
required for #723
follow-up of metasfresh/metasfresh#3078

What is the current behavior?

No such behavior

What is the expected or desired behavior?

Have a way to easily "plug-in" code which is executed each time user sets a process parameter.

More specific, if a given process class is implementing the IProcessParametersCallout interface:

public interface IProcessParametersCallout
{
	void onParameterChanged(String parameterName);
}

The interface method shall be called each time user is changing a parameter.

Note to IT:

Nothing to test. You can just test the task which required that functionality, i.e. #723, and make sure you get an error message right away in case you didn't scanned the product parameter correctly (i.e. what you fill in that parameter field shall be the same as the shipment schedule's product)

[metas-lc]

IT
tested in #723
and the part with adding the wrong product and receiving a message works fine OK