* Add cpp macro to append wrapped language info to xDS user agent
* Add Python xDS user agent
* fix redefinition error and add macro for wrapped lang version
* clang-format
* Revert xds_api.cc changes
* Use two separate macros
* Yapf
* Regenerate projects
* Include _metadata.py in source distributions
* Attempt to fix quote escaping on Windows
Co-authored-by: Mark D. Roth <roth@google.com>
Richard Belleville