Release an xopen-binary package so users can install xopen[binary]

Inspiration from [`psycopg[binary]`](https://github.com/psycopg/psycopg/blob/bbfc3096/psycopg/pyproject.toml#L65) I would love to be able to simply `pip install xopen[binary]` and get parallel xz, zstd, bz2 out of the box without additional installs outside of the python ecosystem. xopen README also mentions [pigz](https://zlib.net/pigz/) (a parallel version of gzip), but I think isal already provides parallel gz?