* [Python] Generate `.pyi` stub files when `--python-typing` is on.
To support this change, the following modifications were made:
- added a new option to disable `numpy` helpers generation;
- added a new flag to control the target Python version:
`--python-version` can be one of the following:
- `0.x.x` – compatible with any Python version;
- `2.x.x` – compatible with Python 2;
- `3.x.x` – compatible with Python 3.
- added codegen utilities for Python;
- added a note that the generated .py file is empty.
* [Python] Update Bazel build rules.
* [Python] Update Bazel build rules.
* [Python] Run buildifier on BUILD.bazel files.
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Co-authored-by: Derek Bailey <derekbailey@google.com>