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 lines = text.split(/\r\n|\r|\n/);
    const buf = [];
    const totalWidth = width - 2 * hPadding;
    for (const line of lines) {
      const chunks = this._splitLine(line, font, fontSize, totalWidth);
      for (const chunk of chunks) {
        const padding = buf.length === 0 ? hPadding : 0;
        buf.push(
          this._renderText(
            chunk,
            font,
            fontSize,
            width,
            alignment,
            padding,
            -fontSize 
          )
        );
      }
    }
    const renderedText = buf.join("\n");
    return (
      "/Tx BMC q BT " +
      defaultAppearance +
      ` 1 0 0 1 0 ${height} Tm ${renderedText}` +
      " ET Q EMC"
    );
  }
  _splitLine(line, font, fontSize, width) {