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
```
role: "NonStruct",
                    children: [{ type: "content", id: "page2R_mcid0" }],
                  },
                ],
              },
              {
                role: "P",
                children: [
                  {
                    role: "NonStruct",
                    children: [{ type: "content", id: "page2R_mcid1" }],
                  },
                ],
              },
              {
                role: "H2",
                children: [
                  {
                    role: "NonStruct",
                    children: [{ type: "content", id: "page2R_mcid2" }],
                  },
                ],
              },
              {
                role: "P",
                children: [
                  {
                    role: "NonStruct",
                    children: [{ type: "content", id: "page2R_mcid3" }],
                  },