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.
ScrollMode,
  SidebarView,
  SpreadMode,
  TextLayerMode,
} from "./ui_utils.js";
import { AppOptions, compatibilityParams, OptionKind } from "./app_options.js";
import { AutomationEventBus, EventBus } from "./event_utils.js";
import {
  build,
  createPromiseCapability,
  getDocument,
  getFilenameFromUrl,
  getPdfFilenameFromUrl,
  GlobalWorkerOptions,
  InvalidPDFException,
  isPdfFile,
  loadScript,
  MissingPDFException,
  OPS,
  PDFWorker,
  shadow,
  UnexpectedResponseException,
  UNSUPPORTED_FEATURES,
  version,
} from "pdfjs-lib";
import { CursorTool, PDFCursorTools } from "./pdf_cursor_tools.js";
import { LinkTarget, PDFLinkService } from "./pdf_link_service.js";
import { OverlayManager } from "./overlay_manager.js";
import { PasswordPrompt } from "./password_prompt.js";
import { PDFAttachmentViewer } from "./pdf_attachment_viewer.js";