Add type checking

[richardkiss]

No description provided.

[Copilot]

Pull Request Overview

This PR adds type checking support to the chiabip158 package by restructuring it as a proper Python package and providing type annotations.

• Restructures the extension module to be properly packaged under chiabip158.chiabip158
• Adds type stub file with annotations for the PyBIP158 class
• Updates CI configuration to handle the new package structure during testing

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
setup.py	Updates extension module name and adds package configuration with type stub inclusion
chiabip158/init.pyi	Adds type annotations for the PyBIP158 class methods and constructor
chiabip158/init.py	Creates package init file that imports PyBIP158 from the extension module
.github/workflows/build.yml	Modifies CI test command to work around import conflicts with the new package structure

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[altendky]

• needs chiabip158/py.typed added and included in the sdist etc to export the hints
• should run stubtest and mypy ( https://github.com/Chia-Network/chia_rs/blob/af0e3019369e5baf95af6cac41eff3fa3c185423/.github/workflows/benchmark.yml#L77-L95 is an example of stubtest usage) (both should be run across platforms and python versions)

[emlowe]

@BugBot review

[wjblanke]

aok