feat!: GetRequiredBehaviour/HierarchyObject methods added for cleaner null handling

Engine.Core/Extensions/GameManagerExtensions.cs

@@ -1,4 +1,5 @@
 using Syntriax.Engine.Core.Abstract;
+using Syntriax.Engine.Core.Exceptions;
 
 namespace Syntriax.Engine.Core;
 
@@ -6,4 +7,13 @@ public static class GameManagerExtensions
 {
     public static IHierarchyObject InstantiateHierarchyObject(this IGameManager gameManager, params object?[]? args)
         => gameManager.InstantiateHierarchyObject<HierarchyObject>(args);
+
+    public static T GetRequiredHierarchyObject<T>(this IGameManager gameManager) where T : class
+    {
+        foreach (IHierarchyObject hierarchyObject in gameManager)
+            if (hierarchyObject is T @object)
+                return @object;
+
+        throw new HierarchyObjectNotFoundException($"{gameManager.GetType().FullName}({gameManager.Id}) does not contain any {typeof(T).FullName}");
+    }
 }