fix(Core/AI): Improve creature leashing behavior. (#19751)

* Init.

https: //github.com/vmangos/core/commit/7d2f1e2923734ea1b983eeaa0208cfd158d4af02
Co-Authored-By: ratkosrb <35845488+ratkosrb@users.noreply.github.com>

* Hackfix for pets.

* Whoops.

* Correct evade uses.

* Conflict.

* Actually fix grace timer.

* Add visibility distance check.

Creatures should always fail combat checks in the open world if they're outside of visibility distance, might not be the case for worldbosses.

---------

Co-authored-by: ratkosrb <35845488+ratkosrb@users.noreply.github.com>

src/server/game/Entities/Unit/Unit.cpp

@@ -1041,10 +1041,6 @@ uint32 Unit::DealDamage(Unit* attacker, Unit* victim, uint32 damage, CleanDamage
 
         if (!victim->IsPlayer())
         {
-            // Part of Evade mechanics. DoT's and Thorns / Retribution Aura do not contribute to this
-            if (damagetype != DOT && damage > 0 && !victim->GetOwnerGUID().IsPlayer() && (!spellProto || !spellProto->HasAura(SPELL_AURA_DAMAGE_SHIELD)))
-                victim->ToCreature()->SetLastDamagedTime(GameTime::GetGameTime().count() + MAX_AGGRO_RESET_TIME);
-
             if (attacker)
             {
                 if (spellProto && victim->CanHaveThreatList() && !victim->HasUnitState(UNIT_STATE_EVADE) && !victim->IsInCombatWith(attacker))
@@ -10387,6 +10383,8 @@ void Unit::CombatStop(bool includingCast)
     RemoveAllAttackers();
     if (IsPlayer())
         ToPlayer()->SendAttackSwingCancelAttack();     // melee and ranged forced attack cancel
+    if (Creature* pCreature = ToCreature())
+        pCreature->ClearLastLeashExtensionTimePtr();
     ClearInCombat();
 
     // xinef: just in case
@@ -13539,6 +13537,9 @@ void Unit::SetInCombatWith(Unit* enemy, uint32 duration)
             return;
         }
     }
+    if (Creature* pCreature = ToCreature())
+        pCreature->UpdateLeashExtensionTime();
+
     SetInCombatState(false, enemy, duration);
 }