consider different WebSockets clients in Python

[slivingston]

Does any other Python package have higher performance without being more difficult to install (as a dependency of hardshare)?

My motivation to open this issue is that, sometimes, a package of more narrow scope achieves better performance than a generalist-style package. Here, aiohttp includes parts that are not expected to be used by the hardshare client, so perhaps there is some WebSockets-only client that is better.

Try websockets (also, https://websockets.readthedocs.io/en/stable/).

Eventually, httpx might support WebSockets. In that case, related issue is #8

[slivingston]

This issue will be obsolete after completion of changing the implementation to Rust.