Add initial Python module helpers

[daxmawal]

This is an initial PR to check whether maintainers are happy with the proposed Python module helper integration before continuing.

It adds a small speechd_python_modules Python package. These helper modules are installed into the configured Python installation under:
$(pythondir)/speechd_python_modules

Follow-up PRs would add, in order:

• Python equivalents for more C module helper functions/modules needed by Python output modules
• integration of the neural-network Pocket TTS module into speechd
• pause/stop support, finish to translate C functions/modules into Python, and further optimizations

Disclosure: Codex assisted me with Autotools, Autoconf, and review.

[daxmawal]

I'm not sure if src/tests/python_module.at is actually useful for speechd, later, perhaps we could transform this into something equivalent in the latest follow-up PRs to c_api.at once Pocket TTS has been integrated. Or we could just delete it now.

[sthibaul]

This is an initial PR to check whether maintainers are happy with the proposed Python module helper integration before continuing.

Thanks! That looks promising.

[sthibaul]

thanks!