Fix gemini schema's oneOf detection logic.

[samchon]

This pull request includes several changes to the @samchon/openapi package, focusing on improving schema validation and adding new test cases for the Gemini converter. The most important changes include updating the package version, enhancing the validation logic in ChatGptConverter and GeminiConverter, and adding new test cases for schema validation.

Version Update:

• Updated the package version in package.json to 2.0.0-dev.20241129-4.

Validation Enhancements:

• src/converters/ChatGptConverter.ts: Added a new validate function to handle schema validation and updated the existing validation logic to use this function. [1] [2]
• src/converters/GeminiConverter.ts: Added validation logic for handling nullable cases and enum cases within the schema.
• src/converters/LlmConverterV3_1.ts: Introduced an optional validate function in the LlmConverterV3_1 namespace to enhance schema validation.

Test Cases:

• Added a new test case test_gemini_schema_enum to validate enum schemas in test/features/llm/gemini/test_gemini_schema_enum.ts.
• Added a new test case test_gemini_schema_nullable to validate nullable schemas in test/features/llm/gemini/test_gemini_schema_nullable.ts.

Utility Imports:

• src/converters/GeminiConverter.ts: Imported MapUtil to assist with schema transformation logic.

[samchon]

OK, successfully fixed.