handle GRUP in wellState from target

opm/simulators/wells/WellInterfaceGeneric.hpp

@@ -43,6 +43,9 @@ class SummaryState;
 class VFPProperties;
 class WellTestState;
 class WellState;
+class GroupState;
+class Group;
+class Schedule;
 
 class WellInterfaceGeneric {
 public:
@@ -174,6 +177,7 @@ protected:
                                      WellTestState& well_test_state,
                                      DeferredLogger& deferred_logger) const;
 
+
     // definition of the struct OperabilityStatus
     struct OperabilityStatus {
         bool isOperable() const {