implement full Notification-API

ElectronNET.API/Entities/NotificationAction.cs

@@ -0,0 +1,15 @@
+namespace ElectronNET.API.Entities
+{
+    public class NotificationAction
+    {
+        /// <summary>
+        /// The label for the given action.
+        /// </summary>
+        public string Text { get; set; }
+
+        /// <summary>
+        /// The type of action, can be button.
+        /// </summary>
+        public string Type { get; set; }
+    }
+}