Implement dialog to set converter parameters

[pleonex]

Some converters may need additional parameters. For instance and enumeration to know the type of file.

Describe the solution you'd like to see.
The idea is to pop up a dialog where the user can set the values for these parameters. We should support basic parameters only like string, int, enums. We could try to use a PropertyGrid for it.
We should detect it from the constructor arguments and first let the user the choice of what type of constructor (if multiple available).

For some types like DataStream or Node we may want to do some specific behavior like selecting an output file or another node from the tree view.