Present to UIWindow associated with passed in page

[PureWeen]

Description of Change

• Modify the code to just locate the current presenting ViewController opposed to iterating over modal pages
• inspect the UIWindow on the incoming page. If that UIWindow is different from the current UIWindow then present the alert to that UIWindow. Mopups uses a new UIWindow to present its popups, so this will fix the issue by checking the UIWindow on the incoming page. This does require users to call "DisplayAlert" on the ContentPage that's used inside the Mopup popup itself, which seems acceptable for now instead of trying to be too smart and try to figure out what UIWindow to present from.

This scenario changed/broke when moving to MAUI because in XF we used a new UIWindow for all our alerts which always presented on top where as with MAUI we changed that code to just present as a new ViewController

maui/src/Controls/src/Core/Platform/AlertManager/AlertManager.iOS.cs

Line 210 in 108d1bc

pageController.PresentViewControllerAsync(alert, true);

Issues Fixed

Fixes #16321

[davembond]

Hurrah! Thank you.
Will this be available in a Nuget Package or do we need to wait for the next Preview or GA for this one?