Add Isopach - Command Enhancements

Further improved the command dialog and functionality to allow surface adjustments to be made over an area defined by the isopach to facilitate matching grade at project limits or matching grade of e.g. approach and departure roads to bridge decks etc.

The command now supports an Isopach surface that covers an area larger or smaller than the reference surface and that only partially overlaps the reference surface.

We also added the ability to add an offset line to the isopach adjustment area so that the adjustment area ties back to the reference surface creating a vertical step around the adjustment area.

Additional Header Bar commands were added to make this a Work Process Tool.