create cirq_google.api.v2.InternalGate proto

[NoureldinYosri]

This PR:

• Introduces cirq_google.api.v2.InternalGate into program.proto and regenerates the autogenerated py and mypy files.
• Updates ArgValue to also accept lists of strings, ints, and floats.
• Updates circuit_serializer.py and arg_func_langs.py to understand the new types/options for serialization and deserialization.
• Fixes the __repr__ method of InternalGate

originally proposed in #6210

[NoureldinYosri]

@dstrain115 any idea what is happening with the protos test, I built the protos with dev_tools/build-protos.sh as the tests says.

[dstrain115]

Seems fine to me, though it pulled in a bunch of irrelevant changes. Is this due to the upgrade in protobuf libraries and python version?

[NoureldinYosri]

@dstrain115 The test assumes python=3.9. my virtual environment had python=3.10. I fixed the issue and documented the solution in #6214 (comment)

Now this PR is block on the notebooks test which is failing on master #6213