Consider introspecting UIWindowScene

[gongzhang]

UIWindowScene contains a lot of contextual information about the current window, and SwiftUI currently has no corresponding API to get this environment information. Therefore, I propose to support getting the parent UIWindowScene from a View.

Code snippets that may be useful:

struct SomeIntrospectionHelperView: UIViewRepresentable {
    
    func makeUIView(context: Context) -> UnderlyingView {
        UnderlyingView()
    }
    
    func updateUIView(_ view: UnderlyingView, context: Context) {
        
    }
    
    class UnderlyingView: UIView {
        
        init() {
            super.init(frame: .zero)
        }
        
        required init?(coder: NSCoder) {
            super.init(frame: .zero)
        }
        
        override func willMove(toWindow newWindow: UIWindow?) {
            super.willMove(toWindow: newWindow)
            if let scene = newWindow?.windowScene {
                // we got window scene here, 👀 callback introspect delegate...
            }
        }
    }
    
}