feat: time scaling

Engine.Core/Abstract/IGameManager.cs

@@ -32,11 +32,21 @@ public interface IGameManager : IEntity, IEnumerable<IHierarchyObject>
     /// </summary>
     event HierarchyObjectUnRegisteredEventHandler? OnHierarchyObjectUnRegistered;
 
+    /// <summary>
+    /// Current time scale the <see cref="IGameManager"/> operates on.
+    /// </summary>
+    float TimeScale { get; set; }
+
     /// <summary>
     /// Contains time data related to this <see cref="IGameManager"/>.
     /// </summary>
     EngineTime Time { get; }
 
+    /// <summary>
+    /// Contains unscaled time data related to this <see cref="IGameManager"/>.
+    /// </summary>
+    EngineTime UnscaledTime { get; }
+
     /// <summary>
     /// Gets a read-only list of <see cref="IHierarchyObject"/>s managed by the <see cref="IGameManager"/>.
     /// </summary>