Suppress initial temperature field for void bodies
In creating bodies, the initial temperature is one of the variables that is required to be set. Would it be feasible to hide that variable if the VOID material is selected for the body? The exporter still needs to write something for the temperature variable of the BODY namelist (any dummy value like 0 would do), but in the future we might clean that up to make it only required for non-VOID materials too.