Quadlock Handlebar Mount

Updated quadlock mount from jimmysinkers.

Changes include:
- Nothing prevented the mount from rotating and destroying the springs so I added slots.
- I changed the top plate dimensions to be a bit more accurate to what comes with the Quadlock.
- I added a handlebar mount with 20mm m5 screws, washers, and lock washers. The screws go into brass heat inserts from McMaster Carr. The part number for the inserts is: 94459A180 (see .stp file for more details on hardware)

I printed with supports with a support blocker just on the inside where the ortho-planar spring is located. I also did a layer height of 0.2mm so that the parts would break apart more easily.