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
```
constructor(parameters) {
    super(parameters);
    const dict = parameters.dict;
    if (dict.has("IRT")) {
      const rawIRT = dict.getRaw("IRT");
      this.data.inReplyTo = isRef(rawIRT) ? rawIRT.toString() : null;
      const rt = dict.get("RT");
      this.data.replyType = isName(rt) ? rt.name : AnnotationReplyType.REPLY;
    }
    if (this.data.replyType === AnnotationReplyType.GROUP) {
      
      
      const parent = dict.get("IRT");
      this.data.title = stringToPDFString(parent.get("T") || "");
      this.setContents(parent.get("Contents"));
      this.data.contents = this.contents;
      if (!parent.has("CreationDate")) {
        this.data.creationDate = null;
      } else {
        this.setCreationDate(parent.get("CreationDate"));
        this.data.creationDate = this.creationDate;
      }
      if (!parent.has("M")) {
        this.data.modificationDate = null;
      } else {
        this.setModificationDate(parent.get("M"));
        this.data.modificationDate = this.modificationDate;
      }
      this.data.hasPopup = parent.has("Popup");