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
```
const tree = new StructTreePage(structTreeRoot, this.pageDict);
    tree.parse();
    return tree;
  }
  getAnnotationsData(intent) {
    return this._parsedAnnotations.then(function (annotations) {
      const annotationsData = [];
      for (let i = 0, ii = annotations.length; i < ii; i++) {
        
        
        if (
          !intent ||
          (intent === "display" && annotations[i].viewable) ||
          (intent === "print" && annotations[i].printable)
        ) {
          annotationsData.push(annotations[i].data);
        }
      }
      return annotationsData;
    });
  }
  get annotations() {