perf: improved garbage created by tweens slightly

They still do generate a lot of garbage but with boxed value pools I made the boxes reusable, it still does generate garbage through the delegate creation, gotta find a solution for them later

Engine.Systems/Tween/Helpers/Boxed.cs

@@ -0,0 +1,12 @@
+using Engine.Core;
+
+namespace Engine.Systems.Tween;
+
+public class Boxed<T> where T : struct
+{
+    public Event<Boxed<T>, BoxedValueChangedArguments> OnValueChanged { get; } = new();
+
+    public T Value { get; set; } = default;
+
+    public readonly record struct BoxedValueChangedArguments(T PreviousValue, T CurrentValue);
+}