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.pdfLinkService.setHash(storedHash);
    }
    
    
    this.toolbar.setPageNumber(
      this.pdfViewer.currentPageNumber,
      this.pdfViewer.currentPageLabel
    );
    this.secondaryToolbar.setPageNumber(this.pdfViewer.currentPageNumber);
    if (!this.pdfViewer.currentScaleValue) {
      
      
      this.pdfViewer.currentScaleValue = DEFAULT_SCALE_VALUE;
    }
  },
  /**
   * @private
   */
  _cleanup() {
    if (!this.pdfDocument) {
      return; 
    }
    this.pdfViewer.cleanup();
    this.pdfThumbnailViewer.cleanup();
    
    this.pdfDocument.cleanup(
       this.pdfViewer.renderer === RendererType.SVG
    );
  },
  forceRendering() {