enable MultiSelectionPrompt and SelectionPrompt to show Renderables as select items.

[nils-a]

Having thought a bit about #550 - is there a particular reason for having the Converter as Action<T, string> - I feel Action<T, IRenderable> should also be possible.

(Not sure, why I would add a progress bar as an item in a prompt, but I see no obvious reason why it shouldn't work)

If you don't mind, I'd think I'd like to take a stab at it. 😁
(That change would probably be breaking, though.)

[patriksvensson]

@nils-a go ahead and take a stab at it 😄

[Armando-CodeCafe]

Was this ever implemented? would be dope as i have an array of panels i would love to scroll through using this without having to instead just "serialize" them myself first and just using a regular selectionprompt