Populate third party license meta data

Is it possible to extend the aspect such that third party license information would be automatically populated?

For example [`pip_parse`](https://github.com/bazelbuild/rules_python#using-a-workspace-file-1) should expose the Python license meta information ([`setup.py license=`](https://packaging.python.org/en/latest/guides/distributing-packages-using-setuptools/#license), [`pyproject.toml license=](https://python-poetry.org/docs/pyproject/#license), [`License ::` classifier](https://pypi.org/classifiers/)).

Start by tracing how pip_parse exposes package metadata, then compare the license sources named in setup.py, pyproject.toml, and the PyPI License classifier. Define how the aspect should expose that information and how completion would be verified across these metadata formats.

Written by the indexing model from the issue text.