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.pdfDocument = pdfDocument;
    pdfDocument.getDownloadInfo().then(({ length }) => {
      this._contentLength = length; 
      this.downloadComplete = true;
      this.loadingBar.hide();
      firstPagePromise.then(() => {
        this.eventBus.dispatch("documentloaded", { source: this });
      });
    });
    
    
    const pageLayoutPromise = pdfDocument.getPageLayout().catch(function () {
      
    });
    const pageModePromise = pdfDocument.getPageMode().catch(function () {
      
    });
    const openActionPromise = pdfDocument.getOpenAction().catch(function () {
      
    });
    this.toolbar.setPagesCount(pdfDocument.numPages, false);
    this.secondaryToolbar.setPagesCount(pdfDocument.numPages);
    let baseDocumentUrl;
    if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
      baseDocumentUrl = null;
    } else if (PDFJSDev.test("MOZCENTRAL")) {
      baseDocumentUrl = this.baseUrl;
    } else if (PDFJSDev.test("CHROME")) {
      baseDocumentUrl = location.href.split("#")[0];