Core/Auras: Remove aura 490 implementation (purpose unknown, needs more spell examples)

Port From (https://github.com/TrinityCore/TrinityCore/commit/342eefcb361900741c17cc40a48fd10436908175)

Source/Framework/Constants/BattleGroundsConst.cs

@@ -88,6 +88,8 @@ namespace Framework.Constants
         public const uint SpellAuraPlayerInactive = 43681;                // Inactive
         public const uint SpellHonorableDefender25y = 68652;                // +50% Honor When Standing At A Capture Point That You Control, 25yards Radius (Added In 3.2)
         public const uint SpellHonorableDefender60y = 66157;              // +50% Honor When Standing At A Capture Point That You Control, 60yards Radius (Added In 3.2), Probably For 40+ Player Battlegrounds
+        public const uint SpellMercenaryContractHorde = 193472;
+        public const uint SpellMercenaryContractAlliance = 193475;
         public const uint SpellMercenaryHorde1 = 193864;
         public const uint SpellMercenaryHordeReactions = 195838;
         public const uint SpellMercenaryAlliance1 = 193863;

Source/Framework/Constants/PlayerConst.cs

@@ -77,10 +77,6 @@ namespace Framework.Constants
 
         //Warmode
         public const uint WarmodeEnlistedSpellOutside = 269083;
-
-        //Mercenary System
-        public const uint  SpellMercenaryContractHorde = 193472;
-        public const uint SpellMercenaryContractAlliance = 193475;
     }
 
     public struct MoneyConstants

Source/Framework/Constants/Spells/SpellAuraConst.cs

@@ -511,7 +511,7 @@ namespace Framework.Constants
         CosmeticMounted = 487,
         Unk488 = 488,
         ModAlternativeDefaultLanguage = 489, // NYI
-        SwitchTeam = 490,
+        Unk490 = 490,
         Unk491 = 491,
         Unk492 = 492,
         Unk493 = 493,