perf: regular events to custom events

Engine.Core/Abstract/Assignable/IHasUniverseObject.cs

@@ -8,7 +8,7 @@ public interface IHasUniverseObject : IAssignable
     /// <summary>
     /// Event triggered when the <see cref="IUniverseObject"/> value has has been assigned a new value.
     /// </summary>
-    event UniverseObjectAssignedEventHandler? OnUniverseObjectAssigned;
+    Event<IHasUniverseObject> OnUniverseObjectAssigned { get; }
 
     /// <inheritdoc cref="IUniverseObject" />
     IUniverseObject UniverseObject { get; }