feat: add WebFlux transport support to WebMVC integration tests

- Enhance McpStreamableServerSession error handling with proper JSON-RPC error responses
- Add mcp-spring-webflux test dependency to webmvc module
- Refactor WebMvcStreamableIntegrationTests to use parameterized tests
- Support testing with both HttpClient and WebFlux transports
- Add WebClientStreamableHttpTransport integration
- Improve error handling in McpStreamableServerSession
- Add proper timeout configurations for test clients
- Clean up test structure and imports organization

This enables comprehensive testing of WebMVC functionality with multiple
transport mechanisms, ensuring compatibility across different client types.

Signed-off-by: Christian Tzolov <[email protected]>

Author: tzolov

mcp-spring/mcp-spring-webmvc/pom.xml

@@ -28,17 +28,24 @@
 			<version>0.11.0-SNAPSHOT</version>
 		</dependency>
 
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-webmvc</artifactId>
+			<version>${springframework.version}</version>
+		</dependency>
+
 		<dependency>
 			<groupId>io.modelcontextprotocol.sdk</groupId>
 			<artifactId>mcp-test</artifactId>
 			<version>0.11.0-SNAPSHOT</version>
 			<scope>test</scope>
 		</dependency>
 
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-webmvc</artifactId>
-			<version>${springframework.version}</version>
+				<dependency>
+			<groupId>io.modelcontextprotocol.sdk</groupId>
+			<artifactId>mcp-spring-webflux</artifactId>
+			<version>0.11.0-SNAPSHOT</version>
+			<scope>test</scope>
 		</dependency>