feat(mcp-client): Add non-blocking tools change notification support

- Add toolsChangeNotificationHandler with non-blocking consumer execution using boundedElastic scheduler
- Add toolsChangeConsumer builder method to McpClient for easy configuration
- Add comprehensive test coverage for tools change notifications
- Update documentation with tools change notification features and examples

The implementation ensures consumers are executed non-blockingly on the boundedElastic scheduler,
preventing performance impact from blocking implementations while maintaining proper error handling and logging.

Part of #20

spring-ai-mcp-core/pom.xml

@@ -98,7 +98,14 @@
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<version>4.2.0</version>
+			<scope>test</scope>
+		</dependency>
+
 	</dependencies>
 
 
-</project>
+</project>