Revert "Don't emit scaleX/Y in the preview event"

This reverts commit fd770eca.

The scale factor was used to restore the previous position. Not sure
why it's needed, but revert for now.

src/vpu-pdf-preview.js

@@ -378,6 +378,8 @@ export class PdfPreview extends ScopedElementsMixin(VPULitElement) {
 
         const data = {
             "currentPage": this.currentPage,
+            "scaleX": item.get("scaleX") / this.canvasToPdfScale,
+            "scaleY": item.get("scaleY") / this.canvasToPdfScale,
             "width": item.get("width") * item.get("scaleX") / this.canvasToPdfScale,
             "height": item.get("height") * item.get("scaleY") / this.canvasToPdfScale,
             "left": left / this.canvasToPdfScale,