Refactor project from Ghost.App to Ghost.Editor

Changed the project structure to reflect a shift from `Ghost.App` to `Ghost.Editor`, updating namespaces and class names throughout.

Changed the application class in `App.xaml` and `App.xaml.cs` from `GhostApplication` to `EditorApplication`.

Changed several service interfaces to reside under `Ghost.Editor.Services.Contracts`, including `IInspectorService`, `INotificationService`, and `IProgressService`.

Added `InspectorView` and `InspectorViewModel` classes to manage inspector functionality.

Added `NavigationTabView` and `NavigationTabPage` classes to facilitate navigation within the editor.

Enhanced `WorldNode` and `EntityNode` classes to support scene graph functionality, including serialization and entity management.

Updated the project file `Ghost.Editor.csproj` to reflect the new structure and removed old references.

Modified the solution file `GhostEngine.sln` to remove references to `Ghost.App` and include `Ghost.Editor`.

Updated unit tests to align with the new namespaces and project structure.

Ghost.App/View/Pages/EngineEditor/InspectorPage.xaml.cs

@@ -0,0 +1,36 @@
+using Ghost.Editor.Controls.Internal;
+using Ghost.Editor.ViewModels.Pages.EngineEditor;
+using Microsoft.UI.Xaml.Controls;
+
+namespace Ghost.Editor.View.Pages.EngineEditor;
+
+internal sealed partial class InspectorPage : NavigationTabPage
+{
+    public InspectorViewModel ViewModel
+    {
+        get;
+    }
+
+    public InspectorPage()
+    {
+        ViewModel = EditorApplication.GetService<InspectorViewModel>();
+
+        InitializeComponent();
+
+        Header = "Inspector";
+        IconSource = new FontIconSource
+        {
+            Glyph = "\uEC7A"
+        };
+    }
+
+    public override void OnNavigatedTo(object? parameter)
+    {
+        ViewModel.OnNavigatedTo(parameter);
+    }
+
+    public override void OnNavigatedFrom()
+    {
+        ViewModel.OnNavigatedFrom();
+    }
+}