fix: PolygonRef::simplify early catch for duplicate points in polygons (CURA-1966)
fix: PolygonRef::simplify early catch for duplicate points in polygons (CURA-1966)

ROBO3D/CuraEngine,alephobjects/CuraEngine,alephobjects/CuraEngine,ROBO3D/CuraEngine,totalretribution/CuraEngine,Ultimaker/CuraEngine,Ultimaker/CuraEngine,totalretribution/CuraEngine,alephobjects/CuraEngine,totalretribution/CuraEngine,ROBO3D/CuraEngine