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.
return this.pdfDocument ? this.pdfDocument.numPages : 0;
  },
  get page() {
    return this.pdfViewer.currentPageNumber;
  },
  set page(val) {
    this.pdfViewer.currentPageNumber = val;
  },
  get supportsPrinting() {
    return PDFPrintServiceFactory.instance.supportsPrinting;
  },
  get supportsFullscreen() {
    if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
      return shadow(this, "supportsFullscreen", document.fullscreenEnabled);
    }
    return shadow(
      this,
      "supportsFullscreen",
      document.fullscreenEnabled ||
        document.mozFullScreenEnabled ||
        document.webkitFullscreenEnabled
    );
  },
  get supportsIntegratedFind() {
    return this.externalServices.supportsIntegratedFind;
  },
  get supportsDocumentFonts() {
    return this.externalServices.supportsDocumentFonts;
  },
  get loadingBar() {