How can I retain the scroll position of the page with the InfiniteHits cache in InstantSearch JS?

Since the list of hits is rendered dynamically, the default browser scroll restoration won't work. In this case we need to save and restore the scroll position manually. Here’s a version for InstantSearch.js.

Note that we need to apply a slight delay before restoring the scroll position which might need to be fine tuned, because we don’t know exactly when the hits themselves are rendered.