Enumerations not in appdef are not checked

[rettigl]

The dataconverter does not check the validity of enumerations, if they are not part of the "nexus_tree" spanned by the application definition explicitly, I.e. for fields that are added from the base_class tree(s).
This is handled here:

pynxtools/src/pynxtools/dataconverter/validation.py

Line 589 in 5f1cd37

continue

and just continues if a field is documented, without checking if it contains valid data.

[rettigl]

@lukaspie Do you have a suggestion? Or is this by design?