changes based on Marc PRs for supporting complex ForwardRef

[srivatsankrishnan]

This is based on the original implementation by Marc for issues relating to passing the null_tokenizer and PackedSequence using Nemo Run CLI.

@run.cli.factory(target=MockDataModule, target_arg="tokenizer")
@run.autoconvert
def null_tokenizer()-> run.Config[AutoTokenizer]:
    return run.Config(
        get_nmt_tokenizer, library="null", model_name="NullTokenizer", vocab_size=256000
    )

Currently modified and the unit test seems to work. Will test on real use needed for me.