Add DashboardWindow, controlls to close the login than open the dashboard

Server Dashboard/ViewModels/Interfaces/IWindowHelper.cs

@@ -0,0 +1,9 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Server_Dashboard {
+    interface IWindowHelper {
+        Action Close { get; set; }
+    }
+}