3mf reader now uses libSavitar for loading
3mf reader now uses libSavitar for loading

This greatly decreases (~factor 10) the time required to load 3mf files

CURA-3215

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