Core/Auras: Implement SPELL_AURA_MOD_HONOR_GAIN_PCT (SPELL_AURA_491)

Port From (https://github.com/TrinityCore/TrinityCore/commit/65279aadf6b31ff8da12b327ce5289a6efe2ec4b)

Source/Framework/Constants/Spells/SpellAuraConst.cs

@@ -498,7 +498,7 @@ namespace Framework.Constants
         DisableGravity = 488,
         ModAlternativeDefaultLanguage = 489, // NYI
         Unk490 = 490,
-        Unk491 = 491,
+        ModHonorGainPct = 491,
         Unk492 = 492,
         Unk493 = 493,
         SetPowerPointCharge = 494, // NYI

Source/Game/Entities/Player/Player.PvP.cs

@@ -147,6 +147,7 @@ namespace Game.Entities
 
                 // apply honor multiplier from aura (not stacking-get highest)
                 MathFunctions.AddPct(ref honor_f, GetMaxPositiveAuraModifierByMiscMask(AuraType.ModHonorGainPctFromSource, 1u << (int)source));
+                MathFunctions.AddPct(ref honor_f, GetMaxPositiveAuraModifier(AuraType.ModHonorGainPct));
                 honor_f += _restMgr.GetRestBonusFor(RestTypes.Honor, (uint)honor_f);
             }