lib.crossLists is deprecated, use lib.cartesianProductOfSets instead

There’s a change in that PR that represents my use case actually, and the answer seems to be use map + cartesianProductOfSets as opposed to just the latter.

I can submit a PR to fix the deprecated message if this is the intention, but wondering can we still have a non-deprecated lib.lists.crossLists function implemented on top of those two functions?