NH-11537 NH-11539 add tox linting and formatting

[tammy-baylis-swi]

This adds NH Python code linting and formatting ways similar to OTel Python's as far as I understand right now:

1. linting and formatting with tox (see CONTRIBUTING diff in this PR for how to run)
2. GH workflow check with CodeQL

I've ported over a lot of the OTel Python settings for what to specifically exclude, how to format the results, which rules to disable, etc. I've not really included anything from AO Python.

black and isort can perform some autofixing. There is no autofixing available with flake8 and there probably never will be. I think it's the same for pylint but I can't find it in its own official docs.

This doesn't enforce formatting with any hooks nor upon-PR action triggers yet. I think I want to do this:

1. Merge this PR if it looks good for a first iteration
2. In a 2nd PR, make actual fixes to the code formatting! It'll be the autofix results plus some manual fixes identified so far and there's quite a few.
3. In a 3rd PR, when all linting/formatting passes, add a new GH workflow to run linting/formatting like Otel Python does with Core Repo tests. It will run at one or more of push and PR, and will error if even a single lint/format issue identified.

I also think I'll be able to test the CodeQL GH workflow once this has been merged to main.

Please let me know what you think! 😺

[cheempz]

LGTM, thanks @tammy-baylis-swi for the analysis and writeup as always. Note that CodeQL may not be available to us yet per separate Jira/email thread that I just cc'd you in.