Set party stats on pkm create

Party stats are stored in box format

PKHeX.Core/MysteryGifts/WC8.cs

@@ -428,6 +428,7 @@ public override PKM ConvertToPKM(ITrainerInfo sav, EncounterCriteria criteria)
                 pk.WeightScalar = PokeSizeUtil.GetRandomScalar();
             }
 
+            pk.ResetPartyStats();
             pk.RefreshChecksum();
             return pk;
         }