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
```
constructor(parameters) {
    /
    super(parameters);
    this.data.annotationType = AnnotationType.POLYGON;
  }
}
class CaretAnnotation extends MarkupAnnotation {
  constructor(parameters) {
    super(parameters);
    this.data.annotationType = AnnotationType.CARET;
  }
}
class InkAnnotation extends MarkupAnnotation {