Provide a mecanism to avoid storing some input parameter to the .ows

As of today all input parameters are saved in a Which is very convenient to load / save those input values.

But when input values are huge (like in darfix - the dataset can contain several Go of data) we want to avoid saving some particular input within the .ows.

Else we will end up with .ows making To. As this is a particular use case we can define a variable to register all the input (or output) variable name to ignore. Like a _ewoks_default_inputs_not_dump

related to XRD/darfix!316 (merged)