Refactor activation handling and introduce entity system

Added new `ActivationHandler` class for folder initialization.
Added `ProjectService` class for project-related operations.
Added `Ghost.Entities` project with entity management classes.
Added `EngineEditorWindow` for enhanced user interface.

Changed project files to restructure dependencies and remove unused references.
Changed `ProjectRepository` to use asynchronous methods for improved performance.
Changed data binding in `CreateProjectPage.xaml` and `OpenProjectPage.xaml` to use new data models.
Changed `App.xaml.cs` to utilize the new `ActivationHandler` and include additional services.

Removed `IActivationHandler` interface and integrated its functionality into `ActivationHandler`.
Removed `EditorActivationHandler` as its functionality was merged into `ActivationHandler`.

Updated `AssemblyInfo.cs` to include global using directives for entity types.
Updated image assets to reflect visual resource changes.

Ghost.Engine/Models/Component.cs

@@ -1,5 +1,10 @@
 namespace Ghost.Engine.Models;
 
-public class Component
+public abstract class Component
 {
+    public required GameEntity Owner
+    {
+        get;
+        set;
+    }
 }

Ghost.Engine/Models/GameEntity.cs

@@ -0,0 +1,18 @@
+using System.Collections.ObjectModel;
+
+namespace Ghost.Engine.Models;
+
+public abstract class GameEntity
+{
+    private ObservableCollection<Component> _components = new();
+
+    public GameEntity()
+    {
+        //AddComponent(new Transform());
+    }
+
+    public void AddComponent(Component component)
+    {
+        _components.Add(component);
+    }
+}

Ghost.Engine/Models/GameObject.cs

@@ -1,18 +0,0 @@
-using Ghost.Engine.Components;
-
-namespace Ghost.Engine.Models;
-
-public class GameObject
-{
-    private List<Component> _components = new();
-
-    public GameObject()
-    {
-        AddComponent(new Transform());
-    }
-
-    public void AddComponent(Component component)
-    {
-        _components.Add(component);
-    }
-}