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 font = await this._getFontData(evaluator, task);
    let descent = font.descent;
    if (isNaN(descent)) {
      descent = 0;
    }
    const vPadding = defaultPadding + Math.abs(descent) * fontSize;
    const alignment = this.data.textAlignment;
    if (this.data.multiLine) {
      return this._getMultilineAppearance(
        defaultAppearance,
        value,
        font,
        fontSize,
        totalWidth,
        totalHeight,
        alignment,
        hPadding,
        vPadding
      );
    }
    
    const encodedString = font.encodeString(value).join("");
    if (this.data.comb) {
      return this._getCombAppearance(
        defaultAppearance,
        font,
        encodedString,
        totalWidth,
        hPadding,
        vPadding