F1+F2 Solid Passthrough

I didn't have a need for the pass-through, and it always printed warped anyways because of it “floating", even with supports. This fixes both problems :)

Can be printed in the orientation given. The only supports that are needed are the “connection protrusions” on F2 (See the .3mf file/screenshots for example). The rest, even though it's a slight overhang, prints out beautifully

 Blocked off the passthrough, reorientated