Initial sandwich solution implementation in SheeKit

SheeImplementation-UIViewControllerRepresentable.swift

final class AdaptiveDelegate<Item>: NSObject, UIPopoverPresentationControllerDelegate, UISheetPresentationControllerDelegate where Item : Identifiable {
    weak var sheetHost: SheetHostingController<Item>?
    var dismissedByUserCallback: DismissAction?
    var isInteractiveDismissDisabled = false
    var selectedDetentIdentifierBinding: Binding<UISheetPresentationController.Detent.Identifier?>?

    override init() {
        super.init()
    }

    func presentationControllerDidDismiss(_ presentationController: UIPresentationController) {
        dismissedByUserCallback?()
    }

    func presentationControllerShouldDismiss(_ presentationController: UIPresentationController) -> Bool {
        !isInteractiveDismissDisabled
    }

    func sheetPresentationControllerDidChangeSelectedDetentIdentifier(_ sheetPresentationController: UISheetPresentationController) {
        selectedDetentIdentifierBinding?.wrappedValue = sheetPresentationController.selectedDetentIdentifier
    }
}

final class SheetPresenterController: UIViewController {}

struct SheetPresenterControllerRepresentable<Item>: UIViewControllerRepresentable where Item : Identifiable {
    @Binding var item: Item?
    @Environment(\.shee_isInteractiveDismissDisabled) private var isInteractiveDismissDisabled
    let onDismiss: (() -> Void)?
    
    func makeCoordinator() -> AdaptiveDelegate<Item> { .init() }

    func makeUIViewController(context: Context) -> SheetPresenterController { .init() }

    func updateUIViewController(_ presenter: SheetPresenterController, context: Context) {}
    
    static func dismantleUIViewController(_ presenter: SheetPresenterController, coordinator: AdaptiveDelegate<Item>) {}
}