GH-2429 Add default implementation of isPaused() to Binding

Resolves #2429

core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binder/Binding.java

@@ -62,6 +62,14 @@ public interface Binding<T> extends Pausable {
 	default void stop() {
 	}
 
+	/**
+	 * Will always return false unless overriden.
+	 */
+	@Override
+	default boolean isPaused() {
+		return false;
+	}
+
 	/**
 	 * Pauses the target component represented by this instance if and only if the
 	 * component implements {@link Pausable} interface NOTE: At the time the instance is