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
```
options.ignoreErrors = true;
    promises.length = 0;
    pdfFonts.length = 0;
    const reallyMissingFonts = new Set();
    for (const missing of missingFonts) {
      if (!getXfaFontWidths(`${missing}-Regular`)) {
        
        reallyMissingFonts.add(missing);
      }
    }
    if (reallyMissingFonts.size) {
      missingFonts.push("PdfJS-Fallback");
    }
    for (const missing of missingFonts) {
      if (reallyMissingFonts.has(missing)) {
        continue;
      }
      for (const fontInfo of [
        { name: "Regular", fontWeight: 400, italicAngle: 0 },
        { name: "Bold", fontWeight: 700, italicAngle: 0 },
        { name: "Italic", fontWeight: 400, italicAngle: 12 },
        { name: "BoldItalic", fontWeight: 700, italicAngle: 12 },
      ]) {
        const name = `${missing}-${fontInfo.name}`;
        const widths = getXfaFontWidths(name);
        const dict = new Dict(null);
        dict.set("BaseFont", Name.get(name));
        dict.set("Type", Name.get("Font"));
        dict.set("Subtype", Name.get("TrueType"));
        dict.set("Encoding", Name.get("WinAnsiEncoding"));