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);
    this.data.annotationType = AnnotationType.SQUARE;
    if (!this.appearance) {
      
      const strokeColor = this.color
        ? Array.from(this.color).map(c => c / 255)
        : [0, 0, 0];
      const strokeAlpha = parameters.dict.get("CA");
      
      let fillColor = null,
        interiorColor = parameters.dict.getArray("IC");
      if (interiorColor) {
        interiorColor = getRgbColor(interiorColor);