Prusa Buffer Filament feed

A re-design of the filament feed for the Prusa buffer to fit some PC4 fittings to allow for easier loading and feed of the filament. I hated the "secure the tubes with screws" design. You crimp the tube and if you screw a thread to many you nip the filament increasing drag.

Looked at a couple of other designs (will add pointers to them later!) and ended up designing these using the original part and adding the supports for the PC4 fittings in a way that made printing them so much easier.

Based on https://www.thingiverse.com/thing:3943306

Added on slot numbers to make it easier to identify as well.