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 resourcesPromise = this.loadResources([
      "ColorSpace",
      "ExtGState",
      "Font",
      "Pattern",
      "Properties",
      "Shading",
      "XObject",
    ]);
    const partialEvaluator = new PartialEvaluator({
      xref: this.xref,
      handler,
      pageIndex: this.pageIndex,
      idFactory: this._localIdFactory,
      fontCache: this.fontCache,
      builtInCMapCache: this.builtInCMapCache,
      standardFontDataCache: this.standardFontDataCache,
      globalImageCache: this.globalImageCache,
      options: this.evaluatorOptions,
    });
    const dataPromises = Promise.all([contentStreamPromise, resourcesPromise]);
    const pageListPromise = dataPromises.then(([contentStream]) => {
      const opList = new OperatorList(intent, sink);
      handler.send("StartRenderPage", {
        transparency: partialEvaluator.hasBlendModes(
          this.resources,
          this.nonBlendModesSet
        ),
        pageIndex: this.pageIndex,
        intent,