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
```
replyDict.set("RT", Name.get("Group")
        replyDict.set("T", "Reply Title"
        replyDict.set("Contents", "Reply Text"
        replyDict.set("M", "D:20190523"
        replyDict.set("C", [0.4]
        const popupRef = Ref.get(821, 0
        const popupDict = new Dict(
        popupDict.set("Type", Name.get("Annot")
        popupDict.set("Subtype", Name.get("Popup")
        popupDict.set("T", "Wrong Title"
        popupDict.set("Contents", "Wrong Text"
        popupDict.set("Parent", replyRef
        popupDict.set("M", "D:20190623"
        popupDict.set("C", [0.8]
        replyDict.set("Popup", popupRef
        const xref = new XRefMock([
          { ref: annotationRef, data: annotationDict },
          { ref: replyRef, data: replyDict },
          { ref: popupRef, data: popupDict },
        ]
        annotationDict.assignXref(xref
        popupDict.assignXref(xref
        replyDict.assignXref(xref
        const { data } = await AnnotationFactory.create(
          xref,
          popupRef,
          pdfManagerMock,
          idFactoryMock
        
        expect(data.title).toEqual("Correct Title"