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
```
p = value;
        while (!(desc = Object.getOwnPropertyDescriptor(p, i))) {
          p = Object.getPrototypeOf(p);
        }
        if (typeof desc.value === "undefined") {
          continue;
        }
        if (typeof desc.value === "function" && !value.hasOwnProperty?.(i)) {
          continue;
        }
        result[i] = cloneValue(desc.value);
      }
      return result;
    }
    const cloned = new WeakMap();
    const event = { data: cloneValue(obj) };
    this._deferred.then(() => {
      for (const listener of this._listeners) {
        listener.call(this, event);
      }
    });
  }
  addEventListener(name, listener) {
    this._listeners.push(listener);
  }
  removeEventListener(name, listener) {
    const i = this._listeners.indexOf(listener);
    this._listeners.splice(i, 1);
  }
  terminate() {