[WinUI3]Fix Windows 10 title bar borders (#36429)

* Fix borders for windows in the Settings UI

* Fix HOSTS window

* Fix Advanced Paste

* Fix Environment Variables

* Fix File Locksmith

* Fix Peek, with a caveat

* Fix Registry Preview

* Remove unused imports

* Clean up imports in OobeShellPage

* Move OSVersionHelper from Common.UI up into ManagedCommon

src/settings-ui/Settings.UI/Helpers/StartProcessHelper.cs

@@ -3,8 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics;
-
-using Common.UI;
+using ManagedCommon;
 
 namespace Microsoft.PowerToys.Settings.UI.Helpers
 {