Core/Auras: Allow SPELL_AURA_MECHANIC_IMMUNITY_MASK to apply aoe/chain targeting immunity

Port From (https://github.com/TrinityCore/TrinityCore/commit/ed0b621d1569a14174a9802027b68dbe4329da69)

Source/Framework/Constants/Spells/SpellConst.cs

@@ -2988,4 +2988,12 @@ namespace Framework.Constants
         Area,
         Chain
     }
+
+    [Flags]
+    public enum SpellOtherImmunity
+    {
+        None = 0x0,
+        AoETarget = 0x1,
+        ChainTarget = 0x2
+    }
 }

Source/Framework/Constants/UnitConst.cs

@@ -98,7 +98,8 @@ namespace Framework.Constants
         Dispel = 4,                     // enum DispelType
         Mechanic = 5,                     // enum Mechanics
         Id = 6,
-        Max = 7
+        Other = 7,  //enum SpellOtherImmunity
+        Max
     }