HK/Pixhawk pitot tube holder

v0.3 works well. Still larger than what I want, but it'll do for now. Picture coming soon.
I do have some weird slicing issues at the base. I may just re-export it.
v0.3 - Expanded gaps as tolerances were too tight.

v0.2 - Walls fixed, changed cutout so that the HK tube can actually fit