feat: initial work on python sdk

[j-lanson]

Progress on #784 .

This PR includes the initial work on the Python SDK. The sdk/python subdirectory has been laid out and uses pyproject.toml to define the packaging system. There is a build.sh that builds the SDK into a wheel.

The tests/example-plugin/main.py is for helping to build out the SDK with a working example. Right now the SDK can get to the point just before starting the bidirectional query interface but stops there. I wanted to start getting this looked at to make future additions more manageable to tackle.

In the future the gen folder contents should not be tracked and its contents should be auto-generated as part of build.sh prior to wheel generation.

[alilleybrinker]

I wonder if it would make sense to use uv for this: https://github.com/astral-sh/uv

[j-lanson]

I wonder if it would make sense to use uv for this: https://github.com/astral-sh/uv

Updated to use uv, I like it so far!