common: refactor common library pt2 (#8588)

- remove common lib
- split settings, remove common-md
- move ipc interop/kb_layout to interop
- rename core -> settings, settings -> old_settings
- os-detect header-only; interop -> PowerToysInterop
- split notifications, move single-use headers where they're used
- winstore lib
- rename com utils
- rename Updating and Telemetry projects
- rename core -> settings-ui and remove examples folder
- rename settings-ui folder + consisent common/version include

src/settings-ui/Microsoft.PowerToys.Settings.UI/App.xaml.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.PowerToys.Settings.UI.Helpers;
+using Microsoft.Toolkit.Win32.UI.XamlHost;
+
+namespace Microsoft.PowerToys.Settings.UI
+{
+    public sealed partial class App : XamlApplication
+    {
+        public App()
+        {
+            Initialize();
+
+            // Hide the Xaml Island window
+            var coreWindow = Windows.UI.Core.CoreWindow.GetForCurrentThread();
+            var coreWindowInterop = Interop.GetInterop(coreWindow);
+            NativeMethods.ShowWindow(coreWindowInterop.WindowHandle, Interop.SW_HIDE);
+        }
+    }
+}