QA: Separate footways that are not tagged as crossing

Similar to https://github.com/a-b-street/speedwalk/issues/76

I found ways like https://www.openstreetmap.org/way/1293979477/history that are clearly crossing in the sense that they cross a non-service(…) road but they dont have any crossing tagging.
Sometimes they are cut in the right way like here, where only the tagging is missing.
Sometimes the footway is drawn in one long line "over" the residential road in which case we need to split (https://github.com/a-b-street/speedwalk/issues/4) the crossing part of first.