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.
"quarkxpress",
  "mac os x",
  "microsoft",
  "openoffice",
  "oracle",
  "luradocument",
  "pdf-xchange",
  "antenna house",
  "aspose.cells",
  "fpdf",
];
class DefaultExternalServices {
  constructor() {
    throw new Error("Cannot initialize DefaultExternalServices.");
  }
  static updateFindControlState(data) {}
  static updateFindMatchesCount(data) {}
  static initPassiveLoading(callbacks) {}
  static async fallback(data) {}
  static reportTelemetry(data) {}
  static createDownloadManager(options) {
    throw new Error("Not implemented: createDownloadManager");
  }
  static createPreferences() {
    throw new Error("Not implemented: createPreferences");
  }
  static createL10n(options) {
    throw new Error("Not implemented: createL10n");
  }
  static createScripting(options) {