Changes to allow Extensibility

[haydenflinner]

For example, I use these hooks to do the help doc that I prefer:

class DataclassWrapper(DataclassWrapper_):
    @property
    def title(self) -> str:
        return self.dataclass.__qualname__

    @property
    def description(self) -> str:
        # TODO Don't show dataclass default __doc__
        return self.dataclass.__doc__ or ""

[haydenflinner]

Good idea on both counts, done!