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.ctx.transform(a, b, c, d, e, f);
      this._cachedGetSinglePixelWidth = null;
    }
    
    constructPath(ops, args) {
      const ctx = this.ctx;
      const current = this.current;
      let x = current.x,
        y = current.y;
      for (let i = 0, j = 0, ii = ops.length; i < ii; i++) {
        switch (ops[i] | 0) {
          case OPS.rectangle:
            x = args[j++];
            y = args[j++];
            const width = args[j++];
            const height = args[j++];
            const xw = x + width;
            const yh = y + height;