perf!: events refactored throughout all the project to use Event<> class

All delegate events are refactored to use the Event<TSender> and Event<TSender, TArgument> for performance issues regarding delegate events creating garbage, also this gives us better control on event invocation since C# Delegates did also create unnecessary garbage during Delegate.DynamicInvoke

Engine.Core/Abstract/IBehaviour.cs

@@ -8,12 +8,12 @@ public interface IBehaviour : IEntity, IActive, IHasBehaviourController, IHasSta
     /// <summary>
     /// Event triggered when the priority of the <see cref="IBehaviour"/> changes.
     /// </summary>
-    event PriorityChangedEventHandler? OnPriorityChanged;
+    Event<IBehaviour, PriorityChangedArguments> OnPriorityChanged { get; }
 
     /// <summary>
     /// The priority of the <see cref="IBehaviour"/>.
     /// </summary>
     int Priority { get; set; }
 
-    delegate void PriorityChangedEventHandler(IBehaviour sender, int previousPriority);
+    readonly record struct PriorityChangedArguments(int PreviousPriority);
 }