NH-14860 refactor setuptools config

[tammy-baylis-swi]

Moves as much of the build configs as possible out of setup.py and into setup.cfg, because setup.py is deprecated for this purpose. I also added pyproject.toml with [build-system] metadata that doesn't actually seem to be needed, but I figured we'd make like OTel Python and just say we have such a file. More background info here as you've already seen: https://swicloud.atlassian.net/wiki/spaces/NIT/pages/3137996006/NH+Python+packaging+and+distribution

I did a quick manual test similar to the last PR, doing a Python 3.6 build step by step: https://swicloud.atlassian.net/wiki/spaces/NIT/pages/3140551795/2022-07-04+sdist+generation+with+setup.cfg

This PR also addresses two comments on the last PR:

1. Fixes the Python 3.6 lower boundary, per this comment.
2. Re-adds setup.py logging after switch to vanilla logging, per this comment. But it is a bit noisy because it adds -v to the pip wheel call.

Please let me know what you think!

[cheempz]

LGTM, thanks for the revisit and detailed test write up @tammy-baylis-swi! I'm fine with the verbose output during wheel generation, it's usually good to get more info rather than less during package build to help troubleshoot.

My original comment was actually about the logging during an sdist install, where our custom extension compile (and all that mucking with platform determination + symlinking) in the setup.py is happening on the customer's host. It's still not getting the log messages, but it's also a minor use case so let's set it aside for now -- ideally most customer installs are on platforms supported by our wheels so having to install sdist and go through the compile step may not occur too often.

[tammy-baylis-swi]

My original comment was actually about the logging during an sdist install, where our custom extension compile (and all that mucking with platform determination + symlinking) in the setup.py is happening on the customer's host.

Oh oops!

It's still not getting the log messages, but it's also a minor use case so let's set it aside for now

Ok sounds good. Thanks Lin!