Update `Transition` component to allow to be renderless

[barryofguilder]

I've noticed that the Transition component always renders an element (div by default). There are a lot of Tailwind UI examples that pass a React Fragment component to Transition so it doesn't render anything. Is that possible with Ember? I mainly ask because it's more difficult to implement Tailwind UI code examples with the Ember version since you end up with an extra element in the hierarchy that messes with styling.

Here is an example from Tailwind UI for building a select menu:

<Transition
  show={open}
  as={Fragment}
  leave="transition ease-in duration-100"
  leaveFrom="opacity-100"
  leaveTo="opacity-0"
>