Core/Misc: Rename Unit::AttackedTarget to Unit::AtTargetAttacked to match naming scheme for these notifiers

Port From (https://github.com/TrinityCore/TrinityCore/commit/dabdad3b47d7438327d3ee861eddd68e9bea68b1)

Source/Game/Entities/Unit/Unit.Combat.cs

@@ -506,7 +506,7 @@ namespace Game.Entities
             if ((attType == WeaponAttackType.BaseAttack || attType == WeaponAttackType.OffAttack) && !IsWithinLOSInMap(victim))
                 return;
 
-            AttackedTarget(victim, true);
+            AtTargetAttacked(victim, true);
             RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags.Attacking);
 
             // ignore ranged case
@@ -643,7 +643,7 @@ namespace Game.Entities
             SendCombatLogMessage(packet);
         }
 
-        public void AttackedTarget(Unit target, bool canInitialAggro = true)
+        public void AtTargetAttacked(Unit target, bool canInitialAggro = true)
         {
             if (!target.IsEngaged() && !canInitialAggro)
                 return;

Source/Game/Spells/Spell.cs

@@ -8039,7 +8039,7 @@ namespace Game.Spells
             {
                 Unit unitCaster = spell.GetCaster().ToUnit();
                 if (unitCaster != null)
-                    unitCaster.AttackedTarget(unit, spell.m_spellInfo.HasInitialAggro());
+                    unitCaster.AtTargetAttacked(unit, spell.m_spellInfo.HasInitialAggro());
 
                 if (!unit.IsStandState())
                     unit.SetStandState(UnitStandStateType.Stand);