Multiboard F Clamp Holder

This is an adaptation to a model by Hasslet. The changes are:1. Make it work for Multiboard. Replaced the HSW connectors with MB strong snaps.2. Added a stopper at the end so that the clamps don't slip off of the holder.3. Strengthened the base.4. The profile has both 18mm wide and 22mm wide holders. I recommend printing it horizontally (as it will be mounted) to avoid weakness along layer lines.