Update trade nickname check

reorder for simplicity, add test
Thanks ThePunish3D!

PKHeX.Core/Legality/Verifiers/NicknameVerifier.cs

@@ -411,11 +411,14 @@ private void VerifyTradeOTNick(LegalityAnalysis data, string[] validOT, int inde
 
         private static bool IsNicknameMatch(string nick, PKM pkm, IEncounterable EncounterMatch)
         {
-            if (nick != pkm.Nickname) // if not match, must not be a nicknamed trade && not currently named
-                return !((EncounterTrade)EncounterMatch).IsNicknamed && !pkm.IsNicknamed;
             if (nick == "Quacklin’" && pkm.Nickname == "Quacklin'")
                 return true;
-            return ((EncounterTrade)EncounterMatch).IsNicknamed;
+            var trade = (EncounterTrade) EncounterMatch;
+            if (trade.IsNicknamed != pkm.IsNicknamed)
+                return false;
+            if (nick != pkm.Nickname) // if not match, must not be a nicknamed trade && not currently named
+                return !trade.IsNicknamed && !pkm.IsNicknamed;
+            return true;
         }
     }
 }