RatRig vcore4 combined z constraints

To create room for bracing the frame I combined two components, the z end stop and z lead screw constraint parts. The remix now only uses 2 bolts total instead of three. This is now compact enough to bolt on an 8 inch shelf bracket across that corner to improve rigidity https://www.amazon.com/gp/product/B0C824HGBQ

The left and right versions are mirrors of each other so only posted the right. All three are included in the .3mf file.