Relocate base class VerticalGrid #4002
Description
The location in the generic3g directory has been problematic for some time, but now is in the way of having vertical_grid be an optional argument for MAPL_FieldGet().
We cannot move all subclasses as some depend on StateRegistry which belongs in the generic layer. But the base class does not have that issue.
@pchakraborty mentioning you because you probably care about this.