Since #12241 we have notifications for this when the user navigates away from the viewer, but we do not yet warn when switching documents, which means that if you call e.g. `PDFViewerApplication.open` with a new document (or directly call `BaseViewer.setDocument` when using the viewer components standalone) there won't be any warning about losing form data. This should be addressed.
if (
      (this._wheelUnusedTicks > 0 && ticks < 0) ||
      (this._wheelUnusedTicks < 0 && ticks > 0)
    ) {
      this._wheelUnusedTicks = 0;
    }
    this._wheelUnusedTicks += ticks;
    const wholeTicks =
      Math.sign(this._wheelUnusedTicks) *
      Math.floor(Math.abs(this._wheelUnusedTicks));
    this._wheelUnusedTicks -= wholeTicks;
    return wholeTicks;
  },
  /**
   * Should be called *after* all pages have loaded, or if an error occurred,
   * to unblock the "load" event; see https://bugzilla.mozilla.org/show_bug.cgi?id=1618553
   * @private
   */
  _unblockDocumentLoadEvent() {