VzBot Orbiter adapter with filament sensor

This replaces the CNC version of the Orbiter extruder mount for the VzBot printhead. It might work on the printed VzBot as well - haven't tested and not sure if the mounting pattern is the same. Needs a 4mm ball bearing and four M3 heat set inserts. Designed for 6mm long inserts, but 4mm ones should work fine.