[Bug] Python tests are failing under bazel

[pyalex]

When trying to run tests under bazel bazel test //api/py:api_test --test_output=streamed
all tests are failing with import error. Example:

_________ ERROR collecting api/py/test/lineage/test_parse_group_by.py __________
ImportError while importing test module '/private/var/tmp/_bazel_omoskalenko/916470916a9b457c8ac69ce8ce573113/execroot/chronon/bazel-out/darwin_arm64-fastbuild/bin/api/py/api_test.runfiles/chronon/api/py/test/lineage/test_parse_group_by.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
../../../../../../../../../external/python_3_8_aarch64-apple-darwin/lib/python3.8/importlib/__init__.py:127: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
api/py/test/lineage/test_parse_group_by.py:18: in <module>
    from ai.chronon import group_by
api/py/ai/chronon/group_by.py:20: in <module>
    import ai.chronon.api.ttypes as ttypes
E   ModuleNotFoundError: No module named 'ai.chronon.api'

The root cause of it: there are two identical Python modules named ai.chronon created under two Bazel packages with outputs:

• bazel-out/darwin_arm64-fastbuild/bin/api/py/api_test.runfiles/chronon/api/py/
• bazel-out/darwin_arm64-fastbuild/bin/api/py/api_test.runfiles/chronon/api/thrift/

They both have structure:

ai/
   chronon/
       __init__.py

Both of them added to sys.path. However, Python can't load both of them. When it discovers the first package under chronon/api/py/ it then looks for ai.chronon.api only there.

Possible solutions:

1. Rename module ai.chronon.api -> ai.chronon_api to work around the module loading issue.
2. Move bazel target generating thrift to api/py package.