add google test cases

[knjiang]

This PR adds comprehensive google test cases for all parameters. surprisingly most of the code worked for messages out of the box.

note:

• this PR doesn't test supporting parameters since it's deferred to the next PR.
• this ended up requiring us the patch the generated code because https://github.com/googleapis/googleapis/blob/master/google/ai/generativelanguage/v1beta/generative_service.proto isn't up to date compared to the actual API.

[knjiang]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
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• Support google parameters  #75
• add google test cases #74 👈 (View in Graphite)
• add google roundtrip #70
• testing framework for transformRequest+Response #72
• lingua-wasm bindings for request/response #69
• Add universal param configs #61
• add anthropic messages parameter test cases #59
• add chat completion parameter test cases #58
• add openai responses parameter test cases #54
• main

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[knjiang]

imageConfigParam generated a really large image so added a truncate_large_values helper for scripts so claude wouldn't run out of context.