Hook up relation icons
Split "other" preset into geometry specific fallbacks

This way the name and icon can be geometry-specific.
Special case multipolygon preset icon

Multipolygons have geometry === "area", so normally
wouldn't trigger a 'preset-icon-relation' class.

This preset usually matches only in the case where
the tags are on the outer way and the multipolygon
itself is untagged. Otherwise, a more specific area
preset will match.