Clarify that the support interface comes from the normal support areas
Clarify that the support interface comes from the normal support areas

They are separated from the support areas by these functions.

Contributes to issue CURA-3491.

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