[Fix #1657] Integrate status change events with others (#1663)

The idea is to not continue workflow execution till the listeners are
completed.

Signed-off-by: Francisco Javier Tirado Sarti <ftirados@ibm.com>

Author: fjtirado

impl/core/src/main/java/io/serverlessworkflow/impl/AbstractExecutorServiceHolder.java

@@ -17,23 +17,21 @@
 
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.TimeUnit;
 
-public class DefaultExecutorServiceFactory extends AbstractExecutorServiceHolder {
-
-  private Lock serviceLock = new ReentrantLock();
+public class DefaultExecutorServiceFactory implements ExecutorServiceFactory {
+  private ExecutorService service = Executors.newCachedThreadPool();
 
   @Override
   public ExecutorService get() {
-    try {
-      serviceLock.lock();
-      if (service == null) {
-        service = Executors.newCachedThreadPool();
-      }
-    } finally {
-      serviceLock.unlock();
-    }
     return service;
   }
+
+  @Override
+  public void close() throws Exception {
+    if (!service.isShutdown()) {
+      service.shutdown();
+      service.awaitTermination(2, TimeUnit.SECONDS);
+    }
+  }
 }

impl/core/src/main/java/io/serverlessworkflow/impl/DefaultExecutorServiceFactory.java

@@ -254,7 +254,7 @@ public SchemaValidator getValidator(SchemaInline inline) {
     private WorkflowPositionFactory positionFactory = () -> new QueueWorkflowPosition();
     private WorkflowInstanceIdFactory idFactory;
     private WorkflowScheduler scheduler;
-    private ExecutorServiceFactory executorFactory = new DefaultExecutorServiceFactory();
+    private ExecutorServiceFactory executorFactory;
     private EventConsumer<?, ?> eventConsumer;
     private Collection<EventPublisher> eventPublishers = new ArrayList<>();
     private RuntimeDescriptorFactory descriptorFactory =
@@ -458,7 +458,9 @@ public Builder withCronResolverFactory(CronResolverFactory cronResolverFactory)
     }
 
     public WorkflowApplication build() {
-
+      if (executorFactory == null) {
+        executorFactory = new DefaultExecutorServiceFactory();
+      }
       if (modelFactory == null) {
         modelFactory =
             loadFirst(WorkflowModelFactory.class)