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.Editor/App.xaml.cs

@@ -1,5 +1,7 @@
-using Ghost.Editor.View.Pages;
+using Ghost.Data.Services;
+using Ghost.Editor.View.Pages;
 using Ghost.Editor.View.Windows;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.UI.Xaml;
 using System;
@@ -39,6 +41,8 @@ namespace Ghost.Editor
                 UseContentRoot(AppContext.BaseDirectory).
                 ConfigureServices((context, services) =>
                 {
+                    services.AddTransient<ProjectService>();
+
                     HostHelper.SetupPageService(context, services);
                 })
                 .Build();
@@ -67,7 +71,7 @@ namespace Ghost.Editor
         {
             base.OnLaunched(args);
 
-            EditorActivationHandler.Handle(args);
+            ActivationHandler.Handle(args);
 
             Host.Start();