Implement worker thread for notification service

components/device-mgt/io.entgra.device.mgt.core.device.mgt.common/src/main/java/io/entgra/device/mgt/core/device/mgt/common/notification/mgt/NotificationWorker.java

@@ -0,0 +1,49 @@
+package io.entgra.device.mgt.core.device.mgt.common.notification.mgt;
+
+import java.util.concurrent.*;
+
+public class NotificationWorker {
+    private final BlockingQueue<Notification> taskQueue;
+    private final ThreadPoolExecutor executor;
+    private boolean isInitialized = false;
+
+    public NotificationWorker() {
+        this.taskQueue = new LinkedBlockingQueue<>();
+        this.executor = new ThreadPoolExecutor(2, 4, 60L, TimeUnit.SECONDS, new LinkedBlockingQueue<>());
+    }
+
+    private synchronized void startWorker() {
+        if (!isInitialized) {
+            isInitialized = true;
+            System.out.println("Notification Service Worker Thread initialized.");
+
+            executor.submit(() -> {
+                try {
+                    while (true) {
+                        Notification nextTask = taskQueue.take();
+                        System.out.println("New task added; processing in a separate thread.");
+                        executor.submit(() -> processNotification(nextTask));
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                    System.out.println("Notification processing thread was interrupted, terminating.");
+                }
+            });
+        }
+    }
+
+    public synchronized void addNotificationTask(Notification notification) {
+        taskQueue.offer(notification);
+        startWorker();
+    }
+
+    private void processNotification(Notification notification) {
+        try {
+            System.out.println("Processing task: " + notification);
+        } catch (Exception e) {
+            System.err.println("Failed to process notification: " + notification + " due to " + e.getMessage());
+        }
+        //The logic should be included in the service layer it will be moved in the relevant milestone --> SSE through notification service
+    }
+
+}