Remove code that sets incompatible materials to invalid type
Remove code that sets incompatible materials to invalid type

Instead use the "compatible" metadata entry like we do for nozzles.

Setting the type differently caused all code that looks for materials to
fail because "incompatible_material" is not "material". Since this is
the base file, this meant a lot of materials failed to duplicate
properly which caused crashes.

Contributes to CURA-2821

fieldOfView/Cura,fieldOfView/Cura,Curahelper/Cura,ynotstartups/Wanhao,ynotstartups/Wanhao,hmflash/Cura,hmflash/Cura,Curahelper/Cura