fix(pypi): fix the whl selection algorithm after #2069

[aignas]

It seems that a few things broke in recent commits:

• We are not using the MODULE.bazel.lock file and it seems that it is easy to
  miss when the components in the PyPI extension stop integrating well
  together. This happened during the switch to {abi}_{os}_{plat} target
  platform passing within the code.
• The logger code stopped working in the extension after the recent additions
  to add the rule_name.
• repo_utils.getenv was always getting PATH env var on bazel 6.x.

This PR fixes both cases and updates docs to serve as a better reminder. By
fixing the select_whls code and we can just rely on target platform triples
(ABI, OS, CPU). This gets one step closer to maybe supporting optional
python_version which would address #1708. Whilst at it we are also adding
different status messages for building the wheel from sdist vs just
extracting or downloading the wheel.

Tests:

• Added more unit tests and brought them in line with the rest of the code.
• Checked manually for differences between the MODULE.bazel.lock files in our
  rules_python extension before refactor(pypi): split out more utils and start passing 'abi_os_arch' around #2069 and after this PR and there are no
  differences except in the experimental_target_platforms attribute in
  whl_library. Before this PR you would see that we do not select any wheels
  for e.g. MarkupSafe and we are always building from sdist.

Work towards #260.

[rickeylev]

Before this PR you would see that we do not select any wheels for e.g. MarkupSafe and we are always building from sdist.

Would this show up as the "Fetching repo bla bla ..." step taking a long time? When I was working on the docs yesterday, there were a couple pypi deps (markup safe sounds familiar) that seemed to be taking a long time to become available. I chalked it up slow downloads or because I was modifying the pypi blz code, but maybe it was building it from source in the repo phase.

[aignas]

Correct, it was building MarkupSafe from source, that is why it was taking longer than usual, I'll add a better log message to indicate that, because we can distinguish between that when we pass url to whl_library.