* feat: Added support for enums as arguments for function tools
* feat: Add default value support for function tools
fix: Add more test cases inside `test_build_function_declaration.py` for passing Enums as arguments
* fix: format code with pyink
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Co-authored-by: Wei Sun (Jack) <weisun@google.com>
Co-authored-by: Yvonne Yu <150068659+yyyu-google@users.noreply.github.com>
