Add a python wrapper

[KarelPeeters]

Use cases:

• enable easy profiling and testing of different NN architectures
• make it easier to debug and compare outputs while porting existing models to Kyanite (eg. Llama, Whisper, ...)

Implementation:

• use pyo3
• initially don't worry about sharing memory, but long-term goal

[KarelPeeters]

This has been implemented in kn-python, see https://github.com/KarelPeeters/Kyanite/blob/dca05eb0207b2575ca137af21532a33f5655c231/kn-python/example.py#L11-L30 for an example of how to use it.