Integrate sys.abi_features/sys.abi_info into toolchains when available

[rickeylev]

It looks like Python is going to add a sys.abi_info attribute that gives details about the interpreter's ABI.

https://discuss.python.org/t/add-sys-abi-features-to-make-information-about-the-interpreter-abi-more-accessible/94422

python/cpython#137476

Whatever they do, It should be exposed on our toolchains. We already do something similar for sys.abiflags; this new fields is basically a more structured and improved version of it.

• Add a equivalent field on the toolchain type, since it's specific about the C ABI, it should go on the py-cc toolchain type.
• local_toolchains: inspect it and put its values in the toolchain
• python-build-standalone: ideally, this would go into a file we can read a repo time using starlark. (cross builds may mean the interpreter can't be run directly)