PyBinary interface type

[smartgoo]

Added crate kaspa-python-core (similar to kaspa-wasm-core) to store certain Python specific interface types.

New Rust struct PyBinary to help provide a standard/flexible interface to Python for binary data. PyBinary itself is not exposed to Python as a Python class. Rather, it is used as a parameter type in functions exposed to Python. Specifically for parameters that are of a binary type such as hex string or byte array. PyBinary implements pyo3::conversion::FromPyObject and allows the Python user to pass three different Python types:

• str (of what should be valid hex, will cause error if not)
• list[int] (where int is u8, will cause error if not)
• bytes

This is modeled after BinaryT WASM interface type.