World|Client: Use ClientSubsector::EdgeRings for targeting material fixes
Use the edge rings to limit the scope of missing-material-fixing to the dependent surfaces only (previously every Line::Side referencing the parent sector was considered, regardless of plane mappings and/or whether the side is a boundary of the subsector being fixed).
Next step: Consider plane mappings when choosing fix materials.
World|Client: Use ClientSubsector::EdgeRings for targeting material fixes
Use the edge rings to limit the scope of missing-material-fixing to
the dependent surfaces only (previously every Line::Side referencing
the parent sector was considered, regardless of plane mappings and/or
whether the side is a boundary of the subsector being fixed).
Next step: Consider plane mappings when choosing fix materials.