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/Core/SceneGraph/EntityNode.cs

@@ -0,0 +1,70 @@
+using Ghost.Editor.Contracts;
+using Ghost.Editor.Resources;
+using Ghost.Entities;
+using Microsoft.UI.Text;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Data;
+
+namespace Ghost.Editor.Core.SceneGraph;
+
+public partial class EntityNode : SceneGraphNode
+{
+    private readonly Entity _entity;
+
+    public Entity Entity => _entity;
+    public override SceneGraphNodeType NodeType => SceneGraphNodeType.Entity;
+
+    public EntityNode(Entity entity, string name)
+    {
+        _entity = entity;
+        Name = name;
+    }
+
+    internal EntityNode()
+    {
+    }
+}
+
+public partial class EntityNode : IInspectable
+{
+    public IconSource? Icon => EditorIconSource.entity_24;
+
+    public UIElement? HeaderContent()
+    {
+        var root = new StackPanel()
+        {
+            HorizontalAlignment = HorizontalAlignment.Stretch,
+            VerticalAlignment = VerticalAlignment.Center
+        };
+
+        var nameText = new TextBox
+        {
+            Text = Name,
+            FontWeight = FontWeights.Bold,
+        };
+        var idText = new TextBlock
+        {
+            Text = $"ID: {_entity.ID}",
+            Margin = new Thickness(0, 5, 0, 0),
+        };
+
+        nameText.SetBinding(TextBox.TextProperty, new Binding
+        {
+            Source = this,
+            Path = new PropertyPath(nameof(Name)),
+            Mode = BindingMode.TwoWay,
+            UpdateSourceTrigger = UpdateSourceTrigger.LostFocus,
+        });
+
+        root.Children.Add(nameText);
+        root.Children.Add(idText);
+
+        return root;
+    }
+
+    public UIElement? InspectorContent()
+    {
+        return null;
+    }
+}