Scale zonal flow and turbulence for any ginit_option

A new feature is being added (see PR #219) that allows the zonal flows (ZFs) and/or turbulence to be scaled arbitrarily and independently. However, the feature introduced by that PR can only be used on restarted runs. It would be nice if we could scale ZFs / turbulence for any ginit_option. This enhancement request is to generalise the new feature to any ginit_option.