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 worker = new Worker(workerSrc);
          const messageHandler = new MessageHandler("main", "worker", worker);
          const terminateEarly = () => {
            worker.removeEventListener("error", onWorkerError);
            messageHandler.destroy();
            worker.terminate();
            if (this.destroyed) {
              this._readyCapability.reject(new Error("Worker was destroyed"));
            } else {
              
              
              this._setupFakeWorker();
            }
          };
          const onWorkerError = () => {
            if (!this._webWorker) {
              
              
              terminateEarly();
            }
          };
          worker.addEventListener("error", onWorkerError);
          messageHandler.on("test", data => {
            worker.removeEventListener("error", onWorkerError);
            if (this.destroyed) {
              terminateEarly();
              return; 
            }
            if (data) {