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.
const file = evt.fileInput.files[0];
    if (!viewerCompatibilityParams.disableCreateObjectURL) {
      let url = URL.createObjectURL(file);
      if (file.name) {
        url = { url, originalUrl: file.name };
      }
      PDFViewerApplication.open(url);
    } else {
      PDFViewerApplication.setTitleUsingUrl(file.name);
      
      const fileReader = new FileReader();
      fileReader.onload = function webViewerChangeFileReaderOnload(event) {
        const buffer = event.target.result;
        PDFViewerApplication.open(new Uint8Array(buffer));
      };
      fileReader.readAsArrayBuffer(file);
    }
    
    const appConfig = PDFViewerApplication.appConfig;
    appConfig.toolbar.viewBookmark.hidden = true;
    appConfig.secondaryToolbar.viewBookmarkButton.hidden = true;
    appConfig.toolbar.download.hidden = true;
    appConfig.secondaryToolbar.downloadButton.hidden = true;
  };
  webViewerOpenFile = function (evt) {
    const openFileInputName = PDFViewerApplication.appConfig.openFileInputName;
    document.getElementById(openFileInputName).click();
  };
}
function webViewerPresentationMode() {