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 operatorList = new OperatorList();
    const initialState = {
      font: null,
      clone() {
        return this;
      },
    };
    const { fontName, fontSize } = this.data.defaultAppearanceData;
    await evaluator.handleSetFont(
      this._fieldResources.mergedResources,
      [fontName && Name.get(fontName), fontSize],
       null,
      operatorList,
      task,
      initialState,
       null
    );
    return initialState.font;
  }
  _computeFontSize(height, lineCount) {
    let { fontSize } = this.data.defaultAppearanceData;
    if (!fontSize) {
      
      
      
      const roundWithOneDigit = x => Math.round(x * 10) / 10;