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
```
this.downloadInfoCapability = createPromiseCapability();
    this.setupMessageHandler();
  }
  get annotationStorage() {
    return shadow(this, "annotationStorage", new AnnotationStorage());
  }
  destroy() {
    if (this.destroyCapability) {
      return this.destroyCapability.promise;
    }
    this.destroyed = true;
    this.destroyCapability = createPromiseCapability();
    if (this._passwordCapability) {
      this._passwordCapability.reject(
        new Error("Worker was destroyed during onPassword callback")
      );
    }
    const waitOn = [];
    
    
    for (const page of this.pageCache) {
      if (page) {
        waitOn.push(page._destroy());
      }
    }
    this.pageCache.length = 0;
    this.pagePromises.length = 0;
    
    if (this.hasOwnProperty("annotationStorage")) {
      this.annotationStorage.resetModified();