Allow overriding config attrs in pip_parse-generated install_deps

[jvolkman]

PR Checklist

Please check if your PR fulfills the following requirements:

• [X] Tests for the changes have been added (for bug fixes / features)
• [X] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• [X] Feature (please, look at the "Scope of the project" section in the README.md file)

What is the current behavior?

pip_parse generates a requirements.bzl which can be vendored by rulesets to install Pypi-sourced Python dependencies. But the install_deps function doesn't allow any configuration. Most importantly, it doesn't allow specifying the python_interpreter_target present in the consuming environment.

What is the new behavior?

install_deps now takes an optional **whl_library_kwargs which can be used to override values that were specified when requirements.bzl was generated.

Does this PR introduce a breaking change?

• [ ] Yes
• [X] No