Removed duplicate code of node backend

Frontend traverser needs to be updated

public/functions/rotatePages.js

@@ -0,0 +1,16 @@
+export async function rotatePages (snapshot, rotation, PDFLib) {
+    // Load the original PDF file
+    const pdfDoc = await PDFLib.PDFDocument.load(snapshot, {
+        parseSpeed: PDFLib.ParseSpeeds.Fastest,
+    });
+
+    const pages = pdfDoc.getPages();
+
+    pages.forEach(page => {
+        // Change page size
+        page.setRotation(PDFLib.degrees(rotation))
+    });
+
+    // Serialize the modified document
+    return pdfDoc.save();
+};