feat(FinalizeDocument): aus CommonJobs kopiert, mit einfachen Fehlerbehebungen unter Verwendung von Copilot

- Programmiersprache von VSC zu C# geändert
 - Framework von .NET Framework zu .NET geändert

EnvelopeGenerator.ServiceHost/Jobs/FinalizeDocument/PDFMerger.cs

@@ -0,0 +1,65 @@
+using System.IO;
+using DigitalData.Modules.Base;
+using DigitalData.Modules.Logging;
+using EnvelopeGenerator.ServiceHost.Exceptions;
+using GdPicture14;
+
+namespace EnvelopeGenerator.ServiceHost.Jobs.FinalizeDocument;
+
+public class PDFMerger : BaseClass
+{
+    private readonly AnnotationManager _manager;
+    private readonly LicenseManager _licenseManager;
+
+    private const bool AllowRasterization = true;
+    private const bool AllowVectorization = true;
+
+    private readonly PdfConversionConformance _pdfaConformanceLevel = PdfConversionConformance.PDF_A_1b;
+
+    public PDFMerger(LogConfig logConfig, string gdPictureLicenseKey) : base(logConfig)
+    {
+        _licenseManager = new LicenseManager();
+        _licenseManager.RegisterKEY(gdPictureLicenseKey);
+
+        _manager = new AnnotationManager();
+    }
+
+    public byte[] MergeDocuments(byte[] document, byte[] report)
+    {
+        using var documentStream = new MemoryStream(document);
+        using var reportStream = new MemoryStream(report);
+        using var finalStream = new MemoryStream();
+        using var documentPdf = new GdPicturePDF();
+        using var reportPdf = new GdPicturePDF();
+
+        documentPdf.LoadFromStream(documentStream, true);
+        var status = documentPdf.GetStat();
+        if (status != GdPictureStatus.OK)
+        {
+            throw new MergeDocumentException($"Document could not be loaded: {status}");
+        }
+
+        reportPdf.LoadFromStream(reportStream, true);
+        status = reportPdf.GetStat();
+        if (status != GdPictureStatus.OK)
+        {
+            throw new MergeDocumentException($"Report could not be loaded: {status}");
+        }
+
+        var mergedPdf = documentPdf.Merge2Documents(documentPdf, reportPdf);
+        status = mergedPdf.GetStat();
+        if (status != GdPictureStatus.OK)
+        {
+            throw new MergeDocumentException($"Documents could not be merged: {status}");
+        }
+
+        mergedPdf.ConvertToPDFA(finalStream, _pdfaConformanceLevel, AllowVectorization, AllowRasterization);
+        status = documentPdf.GetStat();
+        if (status != GdPictureStatus.OK)
+        {
+            throw new MergeDocumentException($"Document could not be converted to PDF/A: {status}");
+        }
+
+        return finalStream.ToArray();
+    }
+}