Attach (recommended) or Link to PDF file here: 
[A Sample PDF Clean 0 degree with all annotations-original-rotated.pdf](https://github.com/mozilla/pdf.js/files/6551789/A.Sample.PDF.Clean.0.degree.with.all.annotations-original-rotated.pdf)

Configuration:
- Web browser and its version: all browsers, tested with Chrome and Firefox latest versions.
- Operating system and its version: tested in Windows 10
- PDF.js version: current (online version)

Steps to reproduce the problem:
1. Visit https://mozilla.github.io/pdf.js/web/viewer.html
2. Upload the file above
3. Notice that several annotations such as arrow, freehand & polyline are missing (compared to Acrobat Reader)
![image](https://user-images.githubusercontent.com/45581023/119781014-11d35d00-befd-11eb-8daa-64f15374cf5b.png)


What is the expected behavior?
- Should display all annotations accordingly to Acrobat Reader

What went wrong? 
- Several annotations are missing such as arrow, freehand & polyline
- Opacity property is not supported and cannot be retrieved via getAnnotations 

const glyphs = font.charsToGlyphs(text);
    const scale = fontSize / 1000;
    let width = 0;
    for (const glyph of glyphs) {
      width += glyph.width * scale;
    }
    let shift;
    if (alignment === 1) {
      
      shift = (totalWidth - width) / 2;
    } else if (alignment === 2) {
      
      shift = totalWidth - width - hPadding;
    } else {
      shift = hPadding;
    }
    shift = shift.toFixed(2);
    vPadding = vPadding.toFixed(2);
    return `${shift} ${vPadding} Td (${escapeString(text)}) Tj`;
  }
  /**
   * @private
   */
  _getSaveFieldResources(xref) {