feat: add support for required query parameters

[li3p]

feat: add support for required query parameters based on field behavior annotations

• Add isFieldRequired() method to check for REQUIRED field behavior annotation
• Update _buildQueryParamsV3() to respect field requirements from protobuf annotations
• Replace hardcoded Required: false with dynamic isRequired based on field annotations
• Improve OpenAPI spec accuracy by properly reflecting field requirements in query parameters

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