feat: Simplify usage of ListenerService API - MEED-7009 - Meeds-io/me…

…eds#2116 (#64)

**Is your feature request related to a problem? Please describe.**
Using current implementation of `ListenerService`, it's difficult to trigger and to add event listeners. In fact the source code is very noisy when handling `ListenerService`, by example
-  to add a Listener:
```java
listenerService.addListener("event.to.catch", new EventListener<> {
  public void onEvent(Event<S, D> event) {
     // Code ....
  }
});
```
- to trigger an event:

```java
try {
  listenerService.broadcast("", s, d);
} catch(Exception e) {
  ....
}
```

This change will use `@FuntionalInterface` behavior to allow using Lambda expressions and avoid having to catch a checked exception while broadcasting event.

exo.kernel.component.common/src/main/java/org/exoplatform/services/listener/Listener.java

@@ -29,14 +29,6 @@
  * @author <a href="mailto:[email protected]">Nhu Dinh Thuan</a>
  * @LevelAPI Platform
  */
-public abstract class Listener<S, D> extends BaseComponentPlugin
-{
-
-   /**
-    * This method should be invoked when an event with the same name is
-    * broadcasted
-    * @param event the event instance
-    */
-   public abstract void onEvent(Event<S, D> event) throws Exception;
+public abstract class Listener<S, D> extends BaseComponentPlugin implements ListenerBase<S, D> {
 
 }

exo.kernel.component.common/src/main/java/org/exoplatform/services/listener/ListenerBase.java

@@ -0,0 +1,44 @@
+/*
+ * This file is part of the Meeds project (https://meeds.io/).
+ *
+ * Copyright (C) 2020 - 2024 Meeds Association [email protected]
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.exoplatform.services.listener;
+
+/**
+ * Created by The eXo Platform SAS<br>
+ * This class is registered with the Listener service and is invoked when an
+ * event with the same name is broadcasted. You can have many listeners with the
+ * same name to listen to an event.
+ * 
+ * @author <a href="mailto:[email protected]">Nhu Dinh Thuan</a>
+ * @LevelAPI Platform
+ */
+@FunctionalInterface
+public interface ListenerBase<S, D> {
+
+  /**
+   * This method should be invoked when an event with the same name is
+   * broadcasted
+   * 
+   * @param event the event instance
+   */
+  void onEvent(Event<S, D> event) throws Exception;
+
+  default String getName() {
+    return this.getClass().getName();
+  }
+
+}