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
```
task,
        annotationStorage
      
      expect(appearance).toEqual(
        "/Tx BMC q BT /Helv 5 Tf 1 0 0 1 0 0 Tm" +
          " 2.00 2.00 Td (a value) Tj ET Q EMC"
      
    }
    it("should save choice", async function () {
      choiceWidgetDict.set("Opt", ["A", "B", "C"]
      choiceWidgetDict.set("V", "A"
      const choiceWidgetRef = Ref.get(123, 0
      const xref = new XRefMock([
        { ref: choiceWidgetRef, data: choiceWidgetDict },
      ]
      partialEvaluator.xref = xref;
      const task = new WorkerTask("test save"
      const annotation = await AnnotationFactory.create(
        xref,
        choiceWidgetRef,
        pdfManagerMock,
        idFactoryMock
      
      const annotationStorage = new Map(
      annotationStorage.set(annotation.data.id, { value: "C" }
      const data = await annotation.save(
        partialEvaluator,
        task,
        annotationStorage