new startup process UI for Windows

windows/WinUI/Switcher.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Windows.Controls;
+using System.Threading.Tasks;
+
+namespace WinUI
+{
+    public static class Switcher
+    {
+        public static PageSwitcher pageSwitcher;
+
+        public static void Switch(UserControl newPage)
+        {
+            pageSwitcher.Navigate(newPage);
+        }
+
+        public static void Switch(UserControl newPage, object state)
+        {
+            pageSwitcher.Navigate(newPage, state);
+        }
+    }
+}