Add conveniences for rapid prototyping

[marcpalmer]

If you are rapidly building out the structure of a feature set, it would be nice to not have to create everything fully initially. In particular Actions types.

We could provide a NotImplementedAction that you can use which takes no input and no presenter, and will just crash if performed.

Other possibilities are some syntactic sure for platform-specific prototyping, e.g. an action for tvOS and iOS that takes no input but has a function or wrapper type as presenter, which can include a segue ID and a transition(input:) function that the default action would call, so you can quickly write stuff together:

struct WireframingPresenter { 
    let viewController: UIViewController
    let presentFunction: (input: Any, viewController: UIViewController) -> Void
    init(viewController: UIViewController, present: (input: Any, viewController: UIViewController) -> Void)  {
    ...
    }

    func present(input: Any) {
       presentFunction(input, viewController)
    }
}

final class WireframingAction: Action {
   typealias PresenterType = WireframingPresenter

   static func perform( ... ) {
     presenter.present(input: input)
      ....
   }
}