Runs a callback when the given element or its ancestors were aborted.
This utility function simplifies consumption of the up:fragment:aborted event.
Example
Let's say we want to reload an element after 10 seconds.
If requests for that element were aborted before the
10 seconds are over, we no no longer want to reload:
let timeout = setTimeout(() => up.reload(element), 10000)
up.fragment.onAborted(element, () => clearTimeout(timeout))
