Configuration:
- PDF.js version: 2.0.550

Steps to reproduce the problem:
1. Render document in SVG mode `renderMode="svg"`

What is the expected behavior? (add screenshot)
Rendering annotations same way as they rendered on canvas

What went wrong? (add screenshot)
```
Warning: Unimplemented operator beginAnnotations
Warning: Unimplemented operator endAnnotations
```
if (
      (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
      this._transport.annotationStorage.size <= 0
    ) {
      deprecated(
        "saveDocument called while `annotationStorage` is empty, " +
          "please use the getData-method instead."
      );
    }
    return this._transport.saveDocument();
  }
  /**
   * @returns {Promise<Array<Object> | null>} A promise that is resolved with an
   *   {Array<Object>} containing /AcroForm field data for the JS sandbox,
   *   or `null` when no field data is present in the PDF file.
   */
  getFieldObjects() {
    return this._transport.getFieldObjects();
  }
  /**
   * @returns {Promise<boolean>} A promise that is resolved with `true`
   *   if some /AcroForm fields have JavaScript actions.
   */
  hasJSActions() {