Feature Request: abort request with AbortController signal

Most probably not a small set of developers had run into wanting to abort an ongoing fetch call. For instance an autocomplete input that makes requests as key events are happening, even with a debouncer.

Now in most browsers [`AbortController`](https://developer.mozilla.org/en-US/docs/Web/API/AbortController) API is available in order to fulfill this task.

This issue is an open question for the community if there's interest in including this feature and what we could achieve. I think an extension of `RSAA` is needed at least.

What do you guys think? I could definitely set up some code proposals or tests in the next days if this idea gains traction 😃