BRH v2 - Basic Roll Holder

This is version 2 of my BRH - Basic roll holder.

### Improvements
- Thicker dual (instead of quad) wheel prongs for stronger load handling
- Reduced panel body/wheel material (reduced print time by 1/5 on my cura profile)

Still working out ideas for improvement; Should be compatible with v1.

### This print requires
- no bearings
- no supports

Print the panel with prongs facing up on bed, print wheels either flat side down;
use large brim if worried about warping.