Core/Auras: Implemented OnHeartbeat AuraScript hook and refactored an aurascript to use it as example

Port From (https://github.com/TrinityCore/TrinityCore/commit/55ce5b150f716b6d470af80a9c31adf78e4cc198)

Source/Game/Entities/Unit/Unit.cs

@@ -2562,7 +2562,7 @@ namespace Game.Entities
             // SMSG_FLIGHT_SPLINE_SYNC for cyclic splines
             SendFlightSplineSyncUpdate();
 
-            // Trigger heartbeat procs and generic aura behavior such as food emotes
+            // Trigger heartbeat procs and generic aura behavior such as food emotes and invoking aura script hooks
             TriggerAuraHeartbeat();
 
             // Update Vignette position and visibility

Source/Game/Scripting/SpellScript.cs

@@ -1094,6 +1094,7 @@ namespace Game.Scripting
         // DO NOT OVERRIDE THESE IN SCRIPTS
         public delegate bool AuraCheckAreaTargetDelegate(Unit target);
         public delegate void AuraDispelDelegate(DispelInfo dispelInfo);
+        public delegate void AuraHeartbeatDelegate();
         public delegate void AuraEffectDamageAndHealingCalcFnType(AuraEffect aurEff, Unit victim, ref int damageOrHealing, ref int flatMod, ref float pctMod);
         public delegate void AuraEffectApplicationModeDelegate(AuraEffect aura, AuraEffectHandleModes auraMode);
         public delegate void AuraEffectPeriodicDelegate(AuraEffect aura);
@@ -1135,6 +1136,18 @@ namespace Game.Scripting
             }
         }
 
+        public class AuraHeartbeatHandler
+        {
+            AuraHeartbeatDelegate _callImpl;
+
+            public AuraHeartbeatHandler(AuraHeartbeatDelegate callImpl) { _callImpl = callImpl; }
+
+            public void Call(AuraScript auraScript)
+            {
+                _callImpl();
+            }
+        }
+
         public class EffectBase : EffectHook
         {
             AuraType _effAurName;
@@ -1264,7 +1277,7 @@ namespace Game.Scripting
                 _callImpl(aurEff, victim, ref damageOrHealing, ref flatMod, ref pctMod);
             }
         }
-        
+
         public class EffectApplyHandler : EffectBase
         {
             AuraEffectApplicationModeDelegate _callImpl;
@@ -1601,6 +1614,11 @@ namespace Game.Scripting
         // where function is: void function (DispelInfo dispelInfo);
         public List<AuraDispelHandler> AfterDispel = new();
 
+        // executed on every heartbeat of a unit
+        // example: OnHeartbeat += AuraHeartbeatFn(class::function);
+        // where function is: void function ();
+        public List<AuraHeartbeatHandler> OnHeartbeat = new();
+
         // executed when aura effect is applied with specified mode to target
         // should be used when effect handler preventing/replacing is needed, do not use this hook for triggering spellcasts/removing auras etc - may be unsafe
         // example: OnEffectApply += AuraEffectApplyFn(class.function, EffectIndexSpecifier, EffectAuraNameSpecifier, AuraEffectHandleModes);

Source/Game/Spells/Auras/Aura.cs

@@ -1986,6 +1986,18 @@ namespace Game.Spells
             }
         }
 
+        public void CallScriptOnHeartbeat()
+        {
+            foreach (var script in m_loadedScripts)
+            {
+                script._PrepareScriptCall(AuraScriptHookType.OnHeartbeat);
+                foreach (var onHeartbeat in script.OnHeartbeat)
+                    onHeartbeat.Call(script);
+
+                script._FinishScriptCall();
+            }
+        }
+
         public bool CallScriptEffectApplyHandlers(AuraEffect aurEff, AuraApplication aurApp, AuraEffectHandleModes mode)
         {
             bool preventDefault = false;
@@ -2865,12 +2877,15 @@ namespace Game.Spells
             _staticApplications[target.GetGUID()] |= effMask;
         }
 
-        void Heartbeat()
+        public override void Heartbeat()
         {
             base.Heartbeat();
 
             // Periodic food and drink emote animation
             HandlePeriodicFoodSpellVisualKit();
+
+            // Invoke the OnHeartbeat AuraScript hook
+            CallScriptOnHeartbeat();
         }
 
         void HandlePeriodicFoodSpellVisualKit()