VisionOS Support

[BeauNouvelle]

Compiler complains about UIScreen not being available in VisionOS.
Will need to come up with an alternative.

[ryanlintott]

I'm not sure LookingGlassUI would make sense in visionOS as it works based on the orientation of the device. To get a shimmer effect on visionOS I would need to know the window position and rotation relative to the user which I don't think is possible. Alternatively I could use a metal shader but that would be an entirely different approach so maybe not suited for this package.