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
```
});
        })
        .catch(reason => {
          this._readyCapability.reject(
            new Error(`Setting up fake worker failed: "${reason.message}".`)
          );
        });
    }
    /**
     * Destroys the worker instance.
     */
    destroy() {
      this.destroyed = true;
      if (this._webWorker) {
        
        this._webWorker.terminate();
        this._webWorker = null;
      }
      pdfWorkerPorts.delete(this._port);
      this._port = null;
      if (this._messageHandler) {
        this._messageHandler.destroy();
        this._messageHandler = null;
      }
    }
    /**
     * @param {PDFWorkerParameters} params - The worker initialization
     *   parameters.
     */
    static fromPort(params) {