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 { catalog, linearization } = this;
    if (
      typeof PDFJSDev === "undefined" ||
      PDFJSDev.test("!PRODUCTION || TESTING")
    ) {
      assert(
        linearization && linearization.pageFirst === pageIndex,
        "_getLinearizationPage - invalid pageIndex argument."
      );
    }
    const ref = Ref.get(linearization.objectNumberFirst, 0);
    return this.xref
      .fetchAsync(ref)
      .then(obj => {
        
        if (
          isDict(obj, "Page") ||
          (isDict(obj) && !obj.has("Type") && obj.has("Contents"))
        ) {