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
```
globalImageCache: this.globalImageCache,
        options: this.evaluatorOptions,
      });
      return partialEvaluator.getTextContent({
        stream: contentStream,
        task,
        resources: this.resources,
        normalizeWhitespace,
        includeMarkedContent,
        combineTextItems,
        sink,
      });
    });
  }
  async getStructTree() {
    const structTreeRoot = await this.pdfManager.ensureCatalog(
      "structTreeRoot"
    );
    if (!structTreeRoot) {
      return null;
    }
    const structTree = await this.pdfManager.ensure(this, "_parseStructTree", [
      structTreeRoot,
    ]);
    return structTree.serializable;
  }
  /**
   * @private
   */
  _parseStructTree(structTreeRoot) {