feat(api-doc): support request parameter parsing for RPC types (Dubbo/SOFA/TARS/gRPC)

[eye-gu]

close #6338

Previously, API document generation only supported Spring Web annotation-based parameter parsing (@RequestParam, @RequestPart, path variables), which only works for HTTP/WebSocket/Spring Cloud. RPC types (Dubbo, SOFA, TARS, gRPC) had no request parameter information in generated documents.

Changes

OpenApiUtils - RPC-aware document generation

• Add buildDocumentJson() that dispatches by RPC type:
  • Dubbo/TARS: parse request parameters from Java method signatures
  • gRPC: parse request/response from StreamObserver method pattern
  • Dubbo + Protobuf: parse protobuf message fields via reflection for both request and response
  • HTTP/WebSocket/Spring Cloud: unchanged Spring MVC annotation parsing
• Unify document fields to requestParameters / responseParameters

SOFA - enable API document support

• Refactor SofaServiceEventListener to extend AbstractContextRefreshedEventListener common flow
• Replace custom handler() / onApplicationEvent() with standard getCorrectedClass() + buildApiPath() hooks
• SOFA services now go through the unified API doc registration pipeline

Examples

• Add @ApiModule / @ApiDoc annotations to Dubbo protobuf example services

Impact

• Dubbo/SOFA/TARS/gRPC API documents now include detailed request parameter schemas
• SOFA module gains API document generation capability
• No breaking change for HTTP/WebSocket/Spring Cloud document generation

Make sure that:

• You have read the contribution guidelines.
• You submit test cases (unit or integration tests) that back your changes.
• Your local test passed ./mvnw clean install -Dmaven.javadoc.skip=true.