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
```
opList.addOp(OPS.beginAnnotation, [data.rect, transform, matrix]);
      return evaluator
        .getOperatorList({
          stream: appearance,
          task,
          resources,
          operatorList: opList,
          fallbackFontDict: this._fallbackFontDict,
        })
        .then(() => {
          opList.addOp(OPS.endAnnotation, []);
          this.reset();
          return opList;
        });
    });
  }
  async save(evaluator, task, annotationStorage) {
    return null;
  }
  /**
   * Get field data for usage in JS sandbox.
   *
   * Field object is defined here:
   * https:www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/js_api_reference.pdf#page=16
   *
   * @public
   * @memberof Annotation
   * @returns {Object | null}
   */
  getFieldObject() {