Pip-licenses

* Add type annotations and code formatter

* Fix "pip-licenses" is missing in output of `pip-licenses --with-system` option

* Support for Python 3.11
* Dropped support Python 3.7
* Migrate Docker base image from Alpine to Debian 11-slim
* Breaking changes
* Does not work with PTable and depends on prettytable
* Depend on importlib\_metadata rather than pip

* Search for path defined in [PEP 639](https://peps.python.org/pep-0639/) with `--with-license-file` option
* Dropped support Python 3.6

* Skip directories when detecting license files

* Support pip 21.3 or later