Single-piece filament Y-switch for e3d embedded collets

This is the next iteration of my attempt on material switch, which uses only the collets available here — https://e3d-online.com/embedded-bowden-collets-for-metal-1-75mm-filament (actually, I used the ones taken from the previous iteration's embedded couplings, but I suspect they're compatible, need to check).

This makes the switch even more compact and a bit cheaper too. Feel free to see remix source for more details.