Material properties are modified when units are not n_m

#### Description:

I am creating BHoM to create a SAP2000 model. I use the adapter to launch SAP2000, then a c# script to modify the units to kip.in (I am not aware of a way of doing this using BHoM, it appears that BHoM adapter is hard coded to launch in SI units). As soon as I push some bars into the model, the material is modified (A992Fy50). It seems its a units mismatch issue.

#### Steps to reproduce:

See description above

#### Expected behaviour:

Ability to 1) Define units in adapter, 2) Pushing a bar does not overrwrite any material unless its not defined. If not defined, the material is defined properly based on the units in the launch SAP2000 model.

#### Test file(s):