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 value = storageEntry && storageEntry.value;
    if (value === undefined) {
      return null;
    }
    const defaultValue = this.data.fieldValue === this.data.buttonValue;
    if (defaultValue === value) {
      return null;
    }
    const dict = evaluator.xref.fetchIfRef(this.ref);
    if (!isDict(dict)) {
      return null;
    }
    const xfa = {
      path: stringToPDFString(dict.get("T") || ""),
      value: value ? this.data.buttonValue : "",
    };
    const name = Name.get(value ? this.data.buttonValue : "Off");
    let parentBuffer = null;
    const encrypt = evaluator.xref.encrypt;
    if (value) {
      if (isRef(this.parent)) {
        const parent = evaluator.xref.fetch(this.parent);
        let parentTransform = null;
        if (encrypt) {
          parentTransform = encrypt.createCipherTransform(
            this.parent.num,
            this.parent.gen
          );
        }
        parent.set("V", name);