Root-level perspective transform causes blurry Popups and Flyouts

PopupViewManager and FlyoutViewManager attempt to work around a z-index shadowing issue by forcing a translation along the Z axis. This interacts poorly with the PerspectiveTransform3D set on the React root view (ReactControl), causing Popups and Flyouts to scale and text to become blurry as their Z position increases.

The code in ReactControl.cpp and ReactRootControl.cpp says:

    // Xaml's default projection in 3D is orthographic (all lines are parallel)
    // However React Native's default projection is a one-point perspective.
    // Set a default perspective projection on the main control to mimic this.

However, while React Native's "transform" property supports a perspective setting, its not required. An orthographic transform should be possible.

I suspect this root-level transform should be removed in favor of components independently setting perspective if needed.

Start in ReactControl.cpp and ReactRootControl.cpp, reading the root-level PerspectiveTransform3D setup and its relationship to PopupViewManager and FlyoutViewManager's Z translation. Trace how the root projection affects Popups and Flyouts, then verify that removing or changing the root-level perspective prevents scaling and blurry text while preserving independently requested perspective transforms.