add Utils.GetMatchingCards

Game/AI/AIFunctions.cs

-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using YGOSharp.OCGWrapper.Enums;
 namespace WindBot.Game.AI
@@ -244,6 +245,11 @@ namespace WindBot.Game.AI
             return null;
         }
 
+        public IList<ClientCard> GetMatchingCards(IList<ClientCard> cards, Func<ClientCard, bool> filter)
+        {
+            return cards.Where(card => card != null && filter(card)).ToList();
+        }
+
         public ClientCard GetPZone(int player, int id)
         {
             if (Duel.IsNewRule)