Draft: Resolve "[Document Sealing] Implement PDF parser"

Closes #1

dist/pdfParser.d.ts

@@ -5,5 +5,6 @@ declare class PDFparser {
     readonly config: any;
     constructor(document: Buffer);
     getPDFMeta: () => Promise<IgetMetaResponse>;
+    insertQrCode: (imgBytes: ArrayBuffer) => Promise<ArrayBuffer>;
 }
 export default PDFparser;