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
```
this.appearance = null;
    const appearanceStates = dict.get("AP");
    if (!isDict(appearanceStates)) {
      return;
    }
    
    const normalAppearanceState = appearanceStates.get("N");
    if (isStream(normalAppearanceState)) {
      this.appearance = normalAppearanceState;
      return;
    }
    if (!isDict(normalAppearanceState)) {
      return;
    }
    
    
    const as = dict.get("AS");
    if (!isName(as) || !normalAppearanceState.has(as.name)) {
      return;
    }
    this.appearance = normalAppearanceState.get(as.name);
  }
  loadResources(keys) {