move reserves from gn_forecasts to group_forecasts/reserve_forecasts
Reserves are now group property and should be moved away from gn_forecasts
- current situation requires complicated sums, such as
df_realization_t(f, t)${not sum(gnGroup(grid, node, group), gn_forecasts(restype, node, 'ts_reserveDemand'))}
- such sums could be easily replaced with group_reserves