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 (this.data.checkBox) {
      return this._saveCheckbox(evaluator, task, annotationStorage);
    }
    if (this.data.radioButton) {
      return this._saveRadioButton(evaluator, task, annotationStorage);
    }
    
    return null;
  }
  async _saveCheckbox(evaluator, task, annotationStorage) {
    if (!annotationStorage) {
      return null;
    }
    const storageEntry = annotationStorage.get(this.data.id);
    const value = storageEntry && storageEntry.value;
    if (value === undefined) {
      return null;
    }
    const defaultValue = this.data.fieldValue && this.data.fieldValue !== "Off";
    if (defaultValue === value) {
      return null;
    }