PropertyWrapper: Storage to extend support for more types using `@AppStorage`

_Example1.swift

// RawRepresentable types using Double aren't supported by default by AppStorage
enum Foo: Double, AppStorageConvertible { 
	case a = 1.0
	case b = 1.5
}

struct MyView: View {
	@AppStorage("foo") @Storage private var foo: Foo = .a

	var body: some View {
		Text("\(foo.rawValue)")
		Button("A") { foo = .a }
		Button("B") { foo = .b }
	}
}

_Example2.swift

struct MyView: View {
	// [String] isn't supported by default by AppStorage, `@Storage` supports it for free
	@AppStorage("foo") @Storage private var foo: [String] = []

	var body: some View {
		Text(foos.joined(separator: ","))
		Button("A") { foos.append("A") }
		Button("B") { foos.append("b") }
	}
}

Storage.swift

@propertyWrapper
struct Storage<T: AppStorageConvertible>: RawRepresentable {
	var rawValue: String { wrappedValue.storedValue }
	var wrappedValue: T

	init?(rawValue: String) {
		guard let value = T.init(rawValue) else { return nil }
		self.wrappedValue = value
	}
	init(wrappedValue: T) {
		self.wrappedValue = wrappedValue
	}
}

extension Binding {
	func binding<T>() -> Binding<T> where Value == Storage<T> {
		return .init(
			get: { wrappedValue.wrappedValue },
			set: { value, transaction in
				self.transaction(transaction).wrappedValue.wrappedValue = value
			}
		)
	}
}

protocol AppStorageConvertible {
	init?(_ storedValue: String)
	var storedValue: String { get }
}

extension RawRepresentable where RawValue: LosslessStringConvertible, Self: AppStorageConvertible {
	init?(_ storedValue: String) {
		guard let value = RawValue(storedValue) else { return nil }
		self.init(rawValue: value)
	}
	var storedValue: String {
		String(describing: rawValue)
	}
}

extension Array: AppStorageConvertible where Element: LosslessStringConvertible {
	public init?(_ storedValue: String) {
		let values = storedValue.components(separatedBy: ",")
		self = values.compactMap(Element.init)
	}
	var storedValue: String {
		return map(\.description).joined(separator: ",")
	}
}