Performance issues when scrolling on the home page

[kawazoe]

When running the Uno Playground app on an iPhone 6 with iOS 12, I notice a drop in frame rate when scrolling on the home page of the app. I estimate it to go down to 12-15 FPS during scrolling. This is less visible on an iPhone 6S which only appear to skip a few frames here and there.

All other samples, like the scroll view, homies, list view, animations, etc, DO NOT exhibit this behavior.

[jeromelaban]

Thanks for the feedback! This is partly caused by this issue: xamarin/xamarin-macios#4923

Once the updates get published (most likely with VS16) this will be a lot better.