Expose abort controller in useAsyncList

[CezCz]

🙋 Feature Request

I'd like to be able to abort fetch in useEffect cleanup when my component is detaching.

🤔 Expected Behavior

useAsyncList should expose a method to abort all it's current ongoing fetches.

😯 Current Behavior

Abort is not possible. This causes a following message being thrown to console:
Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method.

[dannify]

I think we should definitely clean up on unmount and we can investigate ways to allow fetches to be aborted directly.