Simba msgs

Moved the URDFParser into the HAL library and made it its own cmake package. It should be standardized, but for now, it's used as-is in CarPlanner and SimBA. The custom protobufs used in SimBA have also been moved to PbMsgs. 
I'd like to not have this sim stuff integrated into the URDFParser. It's a totally different concern.

What do you think @bminortx ?