Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version:
Firefox/Chrome, latest version
- Operating system and its version:
Linux,Windows,mac
- PDF.js version:
v2.12.313
- Is a browser extension:
no

Steps to reproduce the problem:
1. create a custom viewer with 
```
async function getViewer() {
const viewer = await import(/* webpackChunkName: 'pdfviewer' */ 'pdfjs-dist/web/pdf_viewer');
const eventBus = new viewer.EventBus();
return viewer.PDFSinglePageViewer({
        container,
        eventBus,
        useOnlyCssZoom: USE_ONLY_CSS_ZOOM,
        // We can enable text/annotations layers, if needed
        textLayerFactory: new viewer.DefaultTextLayerFactory(),
        annotationLayerFactory: new viewer.DefaultAnnotationLayerFactory(),
        // textLayerMode: TextLayerMode.ENABLE,
        // currently the SVG renderer is not supported
        // and it has problems with telekom documents
        // so it will be disabled until it is feature complete
        // renderer: 'svg'
    });
}
```
2. console prints an error:
```
Unable to get page for page view TypeError: this.linkService._cachedPageNumber is not a function
    ensurePdfPageLoaded_fn base_viewer.js:1502
```
    
Looks like the problem is `IPDFLinkService` which is actually using the default one `this.linkService = options.linkService || new SimpleLinkService();` which does not have this function. of course we can use `PDFLinkService` which will probably work.

return this.isInPresentationMode
      ? false
      : this.container.scrollHeight > this.container.clientHeight;
  }
  /**
   * Helper method for `this._getVisiblePages`. Should only ever be used when
   * the viewer can only display a single page at a time, for example:
   *  - When PresentationMode is active.
   */
  _getCurrentVisiblePage() {
    if (!this.pagesCount) {
      return { views: [] };
    }
    const pageView = this._pages[this._currentPageNumber - 1];
    
    
    const element = pageView.div;
    const view = {
      id: pageView.id,
      x: element.offsetLeft + element.clientLeft,
      y: element.offsetTop + element.clientTop,
      view: pageView,
    };
    const ids = new Set([pageView.id]);
    return { first: view, last: view, views: [view], ids };
  }
  _getVisiblePages() {