When using viewer.js code in an iframe (`web/viewer.html?file=my.pdf"`) and getting a load error like `Error: file origin does not match viewer's` how do I catch this error?  The console reports `app.js:2140 Uncaught (in promise) Error: file origin does not match viewer's`.  I have setup the load listener and am using the `PDFViewerApplication.initializedPromise`.  I was hoping the `PDFViewerApplication.initializedPromise` would reject, but it does not.  I could not find an eventbus event to listen to specifically for load errors either.

I would like to programmatically detect such load errors and dynamically remove the iframe hosting the pdf viewer and instead replace it with my own error messaging.  I can't figure out how to do that.

Configuration:
- Any, but testing on Chrome 97.0.4692.71 64-bit
- Ubuntu 20.04
- PDF.js version:  v2.12.313
- Is a browser extension: No

Steps to reproduce the problem:
1.  Purposely try to load a PDF in a way that would cause the `app.js:2140 Uncaught (in promise) Error: file origin does not match viewer's` error.
this._unblockDocumentLoadEvent();
    this._hideViewBookmark();
    if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
      const { container } = this.appConfig.errorWrapper;
      container.hidden = true;
    }
    if (!this.pdfLoadingTask) {
      return;
    }
    if (
      (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
      this.pdfDocument?.annotationStorage.size > 0 &&
      this._annotationStorageModified
    ) {
      try {
        
        await this.save({ sourceEventType: "save" });
      } catch (reason) {
        
      }
    }
    const promises = [];
    promises.push(this.pdfLoadingTask.destroy());
    this.pdfLoadingTask = null;
    if (this.pdfDocument) {
      this.pdfDocument = null;
      this.pdfThumbnailViewer.setDocument(null);
      this.pdfViewer.setDocument(null);
      this.pdfLinkService.setDocument(null);