This splitsup the raw `[state, dispatch]` to separate `useActions` and `useData` hooks.

This allows us to make the actions themselves simpler and include logic
that doesn't really belong in the reducer itself.

This also allows us to expose data via the `useData` hook that doesn't
belong in the state exposed from the `useReducer` hook.

E.g.: we used to store a `propsRef` from the root `Listbox`, and update
the ref with the new props in a `useEffect`. Now, we will just expose
that information directly via the `useData` hook. This simplifies the
code, removes useEffect's and so on.

If the `isControlled` value changes, then the references to all the
functions changed. Now they won't because of the `useEvent` hooks.