magnet_v22b has top volume redefined as an assembly. Magnet materials
are defined with explicit tag. Materials are defined in gdml script
to make correct radlen and intlen declaration in case future material
budget maps need to be generated.

Magnets have a wider apperature by 300mm, and a
higher opening by 30mm to allow for a redesigned
STS detector.

Fixes magnet_v21b position.

Update trd tag in DEC21 lmvm setup.

magnet_v21a is the shifted verison of v20a
magnet_v21b is the shifted verison of v20b
rich_v21a is the shifted verison of v17a_1e

Shifted by 40cm consistent with the change of coordinates from
old target position to centre of the magnet.

Having seperate translation for pipe_v16c causes problems for inclusion
of MVD. Translation via node shift instead.

Eoin Clerkin authored 4 years ago and Pierre-Alain Loizeau committed 4 years ago

- Adds magnet_v20[a-b] derived on magnet_v18[a-b] through a translation.
=> This removes the need to have an undesired transformation in CbmMagnet.cxx.