Bondtech BMG Upgrade MK3S FDM printable new sensor integrated

This is a remix of the Original Bondtech BMG Upgrade extruder to integrate the new MK3S filament sensor.
I did also some modifications to be friendly printable with FDM printer.
It has 4 point screws to install the stepper motor instead of 3 like the original from Bondtech (edit: restored 3 point screws)
I included n°2 versions of the sensor's cover to use with PC4-M6 or PC4-M10.
This design include the Bear X_carriage modified, for more info look at https://github.com/gregsaun/bear_extruder