Mgheata/vecgeom 278

This branch is the first step moving the ScaledShape to the new helper interfaces. It fixes a double deletion in the destruction of the UnplacedScaledShape. The branch does not do yet the restructuring to use UnplacedVolume interface to communicate with the shape to be scaled, this will be done in a different branch, after all solids are migrated to the new interfaces. The branch is not yet fixing an alignment issue affecting the benchmark in CUDA, I agreed with Philippe to address this separately (he is also looking into this)