CustomMaterial component / Rho parameter is not loaded into FD

[lorinczandrea]

Although I defined in GH, the Rho parameter in FD is zero.

This is dangerous! When using custom materials, the "+Struct. dead load" load cases will produce results with zero values, so the users will get incorrect results.

Suggestion:
I think it would be better to express the Young modulus in N/mm^2 (MPa) or kN/mm^2 (GPa), as we do in FD.