add proxies

[Graeme22]

Description

Adds a proxy parameter to sessions to allow for proxying requests through a proxy server.
Proxies will also apply to web socket connections such as those used in the streamers.

Pre-merge checklist

• Code formatted correctly (check with make lint)
• Code implemented for both sync and async
• Passing tests locally (check with make test, make sure you have TT_USERNAME, TT_PASSWORD, and TT_ACCOUNT environment variables set)
• New tests added (if applicable)

Please note that, in order to pass the tests, you'll need to set up your Tastytrade credentials as repository secrets on your local fork. Read more at CONTRIBUTING.md.

[Graeme22]

Hi @CompiledSteven, are you on websockets>=15? Please run uv sync, your problem is due to installing from git instead of pypi.