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 (heightScale > 2 && paintHeight > 1) {
          newHeight = Math.ceil(paintHeight / 2);
          heightScale /= paintHeight / newHeight;
        }
        tmpCanvas = this.cachedCanvases.getCanvas(
          tmpCanvasId,
          newWidth,
          newHeight
        );
        tmpCtx = tmpCanvas.context;
        tmpCtx.clearRect(0, 0, newWidth, newHeight);
        tmpCtx.drawImage(
          img,
          0,
          0,
          paintWidth,
          paintHeight,
          0,
          0,
          newWidth,
          newHeight
        );
        img = tmpCanvas.canvas;
        paintWidth = newWidth;
        paintHeight = newHeight;
        tmpCanvasId = tmpCanvasId === "prescale1" ? "prescale2" : "prescale1";
      }
      return {
        img,