Secure DIN Rail Mount for CL57Y or CL57T Stepper Motor Driver

This can be used to mount the standard stepper motor drivers on standard DIN Rail.
I fixed the issue of having to tap holes in similar DIN rail mounts by adding space to embed hex nuts.
Works for the following STEPPERONLINE Models:

DM542
DM542Y
DM542T
DM870
3DM580S
DM456AI
DM480AI
DM556
DM556Y
DM556T
DM556RS
CL57Y
CL57T-V41
CL57RS

I fixed the issue of having to tap holes in similar DIN rail mounts by adding space to embed hex nuts. Also I added a rib on the flexure to increase stiffness and added the .step version of this file which i got by converting it from the mesh.