Trash bag holder - multiboard compatible

Remixed to make this holder work with the multiboard system. Added a multiboard rail to the backside of the holder, so you can attach to the multiboard system in any manner of your choosing (i.e. rails, multipoints, pop-ins and so on), essentially working with the same exterior connections as the multibin. The trash bag holder can also be mounted either horizontally, or vertically, depending on your specific set-up or needs. I have also included a slightly shorter version of the trash bag holder, coming in around 130mm high, as I have some different types of trash bags to organise :)