feat: add structured logging support with severity levels

- Add client and server-side logging capabilities with configurable severity levels
- Implement logging message notifications with DEBUG to EMERGENCY levels
- Add logging consumers for client-side log handling
- Update documentation with logging examples and configuration
- Add comprehensive tests for logging functionality
- Fix typo in README.md (notificaiotn -> notification)

- Centralize MCP method names as constants
  - Move all JSON-RPC method names to McpSchema class as static constants
  - Replace hardcoded method strings with constant references in McpAsyncClient
    and McpAsyncServer
  - Update test cases to use new method name constants

Resolves #35

spring-ai-mcp/src/main/java/org/springframework/ai/mcp/spring/McpFunctionCallback.java

@@ -28,7 +28,6 @@ import org.springframework.ai.model.function.FunctionCallback;
 
 /**
  * @author Christian Tzolov
- * @since 1.0.0
  */
 
 public class McpFunctionCallback implements FunctionCallback {