Introduce DeLHCb to be able to have a handle to the whole geometry
Setup a DeLHCb dummy DetectorElement that can act as a replacementfor what you get in DetDesc when you get /dd/Structure/LHCb
After discussion with @sponce, I added a parameter in the constructor of DeIOV to remove the need for an alignment in some cases.
I also completed DeMagnet to provide missing methods from the MagneticFieldSvc
Edited by Ben Couturier