Enhance PDF viewer with annotations and WebAssembly

Added support for advanced annotation tools, including signature and stamp management, along with accessibility improvements. Introduced WebAssembly binaries (`qcms_bg.wasm`, `quickjs-eval.wasm`, `openjpeg.wasm`, `jbig2.wasm`) for enhanced performance in color management, JavaScript execution, and image decoding.

Implemented a JavaScript fallback (`openjpeg_nowasm_fallback.js`) for environments without WebAssembly support. Updated `Details.cshtml` to include a PDF viewer popup and added a new Razor Page (`ViewPdf.cshtml`) for secure PDF file access. Registered `.mjs` MIME type in `Program.cs` for PDF.js compatibility.

Enhanced localization with translations for multiple languages in `viewer.ftl` and added new icons, dialogs, and accessibility features. Updated `DXApp.sln` to include a new project for template management. These changes improve functionality, modularity, and user experience.

DXApp.TemplateKitProject/Pages/Invoices/ViewPdf.cshtml.cs

@@ -0,0 +1,24 @@
+using DXApp.TemplateKitProject.Data;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+using Microsoft.EntityFrameworkCore;
+
+namespace DXApp.TemplateKitProject.Pages.Invoices;
+
+public class ViewPdfModel(AppDbContext db) : PageModel
+{
+    public async Task<IActionResult> OnGetAsync(int id)
+    {
+        var invoice = await db.ZugferdInvoices
+            .FirstOrDefaultAsync(i => i.Id == id);
+
+        if (invoice is null || string.IsNullOrEmpty(invoice.ResultFilePath))
+            return NotFound();
+
+        if (!System.IO.File.Exists(invoice.ResultFilePath))
+            return NotFound();
+
+        var bytes = await System.IO.File.ReadAllBytesAsync(invoice.ResultFilePath);
+        return File(bytes, "application/pdf");
+    }
+}