add ability to send back a chosen title & message

app.py

@@ -450,10 +450,18 @@ class WebPushService():
                     "auth": subscription.auth
                 }
             }
+
+            title = "Test Notification"
+            if "title" in content:
+                title = content['title']
+            message = "This is a test notification."
+            if "message" in content:
+                message = content['message']
+
             vapid_key = VAPIDKey.query.filter_by(id=subscription.vapid_key_id).first()
             result = WebPushService._send_push_notification(
                 subscription_info,
-                {"title": "Test Notification", "message": "This is a test notification"},
+                {"title": title, "message": message},
                 vapid_key
             )
             return jsonify(