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
```
const paths = this.pendingTextPaths;
      const ctx = this.ctx;
      if (paths === undefined) {
        ctx.beginPath();
        return;
      }
      ctx.save();
      ctx.beginPath();
      for (let i = 0; i < paths.length; i++) {
        const path = paths[i];
        ctx.setTransform.apply(ctx, path.transform);
        ctx.translate(path.x, path.y);
        path.addToPath(ctx, path.fontSize);
      }
      ctx.restore();
      ctx.clip();
      ctx.beginPath();
      delete this.pendingTextPaths;
    }
    setCharSpacing(spacing) {
      this.current.charSpacing = spacing;
    }
    setWordSpacing(spacing) {
      this.current.wordSpacing = spacing;
    }
    setHScale(scale) {
      this.current.textHScale = scale / 100;
    }
    setLeading(leading) {