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 (!isWorkerDisabled) {
        warn("Setting up fake worker.");
        isWorkerDisabled = true;
      }
      setupFakeWorkerGlobal()
        .then(WorkerMessageHandler => {
          if (this.destroyed) {
            this._readyCapability.reject(new Error("Worker was destroyed"));
            return;
          }
          const port = new LoopbackPort();
          this._port = port;
          
          const id = "fake" + nextFakeWorkerId++;
          
          
          const workerHandler = new MessageHandler(id + "_worker", id, port);
          WorkerMessageHandler.setup(workerHandler, port);
          const messageHandler = new MessageHandler(id, id + "_worker", port);
          this._messageHandler = messageHandler;
          this._readyCapability.resolve();
          
          messageHandler.send("configure", {
            verbosity: this.verbosity,