Reorganize Python packages

This is in preparation of moving all tests into a separate package to
enable ease of coverage checking and testing.

src/python/src/commands.py → src/python/grpcio/commands.py

@@ -43,6 +43,7 @@ napoleon_numpy_docstring = True
 html_theme = 'sphinx_rtd_theme'
 """
 
+
 class SphinxDocumentation(setuptools.Command):
   """Command to generate documentation via sphinx."""