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
```
this.data.lineCoordinates[3] + borderAdjust,
      ];
      if (!Util.intersect(this.rectangle, bbox)) {
        this.rectangle = bbox;
      }
      this._setDefaultAppearance({
        xref: parameters.xref,
        extra: `${borderWidth} w`,
        strokeColor,
        fillColor,
        strokeAlpha,
        fillAlpha,
        pointsCallback: (buffer, points) => {
          buffer.push(
            `${lineCoordinates[0]} ${lineCoordinates[1]} m`,
            `${lineCoordinates[2]} ${lineCoordinates[3]} l`,
            "S"
          );
          return [
            points[0].x - borderWidth,
            points[1].x + borderWidth,
            points[3].y - borderWidth,
            points[1].y + borderWidth,
          ];
        },
      });
    }
  }
}
class SquareAnnotation extends MarkupAnnotation {