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/Landing/CreateProjectPage.xaml

@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <Page
-    x:Class="Ghost.App.View.Pages.Landing.CreateProjectPage"
+    x:Class="Ghost.Editor.View.Pages.Landing.CreateProjectPage"
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:data="using:Ghost.Data.Models"
     xmlns:editor="using:Ghost.Editor.Controls"
-    xmlns:local="using:Ghost.App.View.Pages.Landing"
+    xmlns:local="using:Ghost.Editor.View.Pages.Landing"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     NavigationCacheMode="Enabled"
     mc:Ignorable="d">