feat(core): IBehavior.IsActive

Engine.Core/Abstract/IBehaviour.cs

@@ -16,4 +16,9 @@ public interface IBehaviour : IEntity, IAssignableBehaviourController, IAssignab
     /// Call priority of the <see cref="IBehaviour"/>.
     /// </summary>
     int Priority { get; set; }
+
+    /// <summary>
+    /// If the <see cref="IBehaviour"/> is active.
+    /// </summary>
+    bool IsActive { get; }
 }