[DMN Designer] Client-side DataObjectsService implementation

The DMN editor's ability to import Java files as ItemDefinition requires the ability to gather meta-data for Java classes present in the underlying FileSystem (or container, e.g. VSCode, Che etc). This is currently handled server-side using the DataModelOracle. The client-side implementation will need to either query the container for Java class meta-data or be able to handle the Java source to extract the meta-data.

eignatow abakos@redhat.com Possibly another requirement of the container?

mmortari@redhat.com requested the following:

1. Is this feature going to be eventually supported in Kogito as well, potentially once a few "Microsoft APIs" and Stunner framework features, will make available to the editor the DMO-equivalent or anyway a service to know which class could be used for this scope?

2. if YES, could the DMN editor note in the ItemDefintion the FQN of the java class which was used?
By means of extra attribute, extensions, etc. whatever is more convenient