Core/Creatures: Reworked setting move types in database

Port From (https://github.com/TrinityCore/TrinityCore/commit/f8c03a90661610e289029c78d2055d7b73a5ad98)

Source/Framework/Database/SQLResult.cs

@@ -121,5 +121,10 @@ namespace Framework.Database
 
             return values;
         }
+
+        public bool IsNull(int column)
+        {
+            return _currentRow[column] == DBNull.Value;
+        }
     }
 }