JSON: moved extruder train specific settings to its own category
JSON: moved extruder train specific settings to its own category

senttech/Cura,markwal/Cura,ynotstartups/Wanhao,ynotstartups/Wanhao,fieldOfView/Cura,bq/Ultimaker-Cura,fxtentacle/Cura,fxtentacle/Cura,hmflash/Cura,Curahelper/Cura,ad1217/Cura,fieldOfView/Cura,Curahelper/Cura,senttech/Cura,markwal/Cura,ad1217/Cura,totalretribution/Cura,totalretribution/Cura,hmflash/Cura,bq/Ultimaker-Cura