Extract AnnotatedMethod base class for consistent annotation exposure

As a consequence, the spring-messaging HandlerMethod detects interface parameter annotations as well, and the same is available for other HandlerMethod variants.

Closes gh-30801

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ServletInvocableHandlerMethod.java

@@ -272,7 +272,7 @@ public class ServletInvocableHandlerMethod extends InvocableHandlerMethod {
 	 * that's null falling back on the generic type within the declared async
 	 * return type, e.g. Foo instead of {@code DeferredResult<Foo>}.
 	 */
-	private class ConcurrentResultMethodParameter extends HandlerMethodParameter {
+	private class ConcurrentResultMethodParameter extends AnnotatedMethodParameter {
 
 		@Nullable
 		private final Object returnValue;