[Settings]Add a link to the OOBE What's New page in the Settings menu (#29028)

* Adds a link to the OOBE What's New Section in the ShellPage Navigation

* Updated verbiage to code as per recommendation

* Updated so that if the Oobe Window is active, clicking on the What's New option in the ShellPage navigates to the What's New page.

Added a "SetActiveWindow" Method the OobeWindow to easily open an active window of a set PowerToysModule type - this is to support being able to open the What's New Page without having to close the Oobe Window and close it every time.

* Renamed SetActiveWindow to SetAppWindow

* Adjusted method and property names for naming consistency across the application

* Fixed an oversight.

---------

Co-authored-by: Ian Kraynak <iakrayna@microsoft.com>

src/settings-ui/Settings.UI/SettingsXAML/OobeWindow.xaml.cs

@@ -105,6 +105,14 @@ namespace Microsoft.PowerToys.Settings.UI
             });
         }
 
+        public void SetAppWindow(PowerToysModules module)
+        {
+            if (shellPage != null)
+            {
+                shellPage.NavigateToModule(module);
+            }
+        }
+
         private void OobeWindow_SizeChanged(object sender, WindowSizeChangedEventArgs args)
         {
             var dpi = NativeMethods.GetDpiForWindow(_hWnd);