Add support for deferred events

- Relates to #262

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryState.java

@@ -89,4 +89,11 @@ public abstract class RepositoryState extends BaseRepositoryEntity {
 	 * @return the pseudo state kind
 	 */
 	public abstract PseudoStateKind getKind();
+
+	/**
+	 * Gets the deferred events.
+	 *
+	 * @return the deferred events
+	 */
+	public abstract Set<String> getDeferredEvents();
 }

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryStateMachineModelFactory.java

@@ -155,6 +155,7 @@ public class RepositoryStateMachineModelFactory extends AbstractStateMachineMode
 					stateData.setEnd(true);
 				}
 			}
+			stateData.setDeferred(s.getDeferredEvents());
 			stateDatas.add(stateData);
 		}
 		StatesData<String, String> statesData = new StatesData<>(stateDatas);