[PTRun]Detect full-screen games with QUNS_RUNNING_D3D_FULL_SCREEN (#30797)

* Add SHQueryUserNotificationState to NativeMethods

* Check for QUNS_RUNNING_D3D_FULL_SCREEN in IsWindowFullscreen

The current test for whether a window is full-screen (i.e. a movie or a game) is a bit of a heuristic. In certain cases however, we can *know* that a window is full-screen. Check that case first, then proceed with the existing logic

* Make spellchecker happier

src/modules/launcher/PowerLauncher/Helper/WindowsInteropHelper.cs

@@ -112,6 +112,15 @@ namespace PowerLauncher.Helper
 
         public static bool IsWindowFullscreen()
         {
+            // First, check to see if a game is fullscreen, if so, we definitely have
+            // a full-screen window
+            UserNotificationState state;
+            if (Marshal.GetExceptionForHR(NativeMethods.SHQueryUserNotificationState(out state)) == null &&
+                state == UserNotificationState.QUNS_RUNNING_D3D_FULL_SCREEN)
+            {
+                return true;
+            }
+
             // get current active window
             IntPtr hWnd = NativeMethods.GetForegroundWindow();