Reapply photobooth uploader changes

clients/photobooth-uploader/PhotoboothUploader/App.xaml.cs

@@ -0,0 +1,17 @@
+using Microsoft.UI.Xaml;
+
+namespace PhotoboothUploader;
+
+public partial class App : Application
+{
+    public App()
+    {
+        InitializeComponent();
+    }
+
+    protected override void OnLaunched(LaunchActivatedEventArgs args)
+    {
+        var window = new MainWindow();
+        window.Activate();
+    }
+}