Refactor PDF viewing and integrate DevExpress support

- Removed folder reference for "Controllers" in the project file.
- Updated `ViewPdf.cshtml` to include layout and clarify PDF output.
- Enhanced `ViewPdf.cshtml.cs` with improved logging and error handling.
- Added MVC controller services in `Program.cs` for DevExpress functionality.
- Introduced `DocumentViewerController` to manage document viewing requests.

DXApp.TemplateKitProject/Controllers/DocumentViewerController.cs

@@ -0,0 +1,16 @@
+using Microsoft.AspNetCore.Mvc;
+using DevExpress.AspNetCore.Reporting.WebDocumentViewer;
+using DevExpress.AspNetCore.Reporting.WebDocumentViewer.Native.Services;
+
+namespace DXApp.TemplateKitProject.Controllers
+{
+    [Route("DocumentViewer")]
+    public class DocumentViewerController : WebDocumentViewerController
+    {
+        // Hier den erwarteten DevExpress-Service injizieren und an die Basisklasse weitergeben
+        public DocumentViewerController(IWebDocumentViewerMvcControllerService controllerService)
+            : base(controllerService)
+        {
+        }
+    }
+}