QA: Separate crossing roads with node but without crossing tags.

I found places like https://www.openstreetmap.org/node/10143138388/history where there is a connection (that iD validates for) of sidewalk and residential road but there is no crossing node and no crossing way.

A QA step might be good to find those places and allow for a quick adding of basic crossing tags.

Look at the existing QA steps in the codebase to understand how they detect OSM tagging issues. The issue describes a specific pattern: a node connecting a sidewalk and a road without crossing tags. Start by finding where sidewalk and road connections are validated in iD or the project's own validation logic. Then write a new QA check that flags these nodes and suggests adding crossing tags. Test with the provided OSM node example.

Written by the indexing model from the issue text.