Flippped octoprint case for Prusa I3 MK3

This is a remix of ChrisPetit's excellent raspberry pi case. I swapped the lid and base and offset the whole thing to the right. The idea is to provide additional space for mounting hats, cables, etc to the raspberry pi. I also enlarged the cutout around the GPIO pins a generous amount so that a stacking header could easily be plugged in.

I've also included a pi-hat cover that can be used as basis for covering a hat that stacks on the outside of the case. The hat cover is setup with cutouts f