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
```
return this._readyCapability.promise;
    }
    get port() {
      return this._port;
    }
    get messageHandler() {
      return this._messageHandler;
    }
    _initializeFromPort(port) {
      this._port = port;
      this._messageHandler = new MessageHandler("main", "worker", port);
      this._messageHandler.on("ready", function () {
        
        
      });
      this._readyCapability.resolve();
    }
    _initialize() {