Draft: introducing muons

This PR introduces a first attempt for MDT muons chambers filled with the tubes for the Muon Spectrometer. The chambers are placed inside three layers as in ATLAS, and there are two sides (A and C). In the pitcure there are the three layers with the chambers and the tubes. Update: Two endcaps that encapsulate the inner barrel layer and the two outer (middle and outer) barrel layers are added as you can see in the pictures (with and without the barrel layers). We decided to use rectangular shape chambers in order to fill with fixed size tubes without having empty space. The chambers with the tubes are also in place for the end caps. To do: Run simulation for the muons