Dependency Group Support

[da1910]

With the release of Poetry 1.2 recently the suggested approach for organising dependencies is now to use groups, rather than the binary dependencies vs. dev-dependencies. Additionally, the need to use extras for things like test or docs dependencies is removed.

Support for these would be very helpful, much in the way this tool allows users to specify extras to be installed as part of a tox env, it should allow users to specify dependency groups for installation or to be omitted.

See: https://python-poetry.org/docs/master/managing-dependencies/#dependency-groups https://python-poetry.org/docs/master/pyproject/#dependencies-and-dependency-groups https://python-poetry.org/docs/master/cli/#install