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 

parentItem = parentItem.get("IRT");
    }
    if (!parentItem.has("M")) {
      this.data.modificationDate = null;
    } else {
      this.setModificationDate(parentItem.get("M"));
      this.data.modificationDate = this.modificationDate;
    }
    if (!parentItem.has("C")) {
      
      this.data.color = null;
    } else {
      this.setColor(parentItem.getArray("C"));
      this.data.color = this.color;
    }
    
    
    
    if (!this.viewable) {
      const parentFlags = parentItem.get("F");
      if (this._isViewable(parentFlags)) {
        this.setFlags(parentFlags);
      }
    }
    this.data.title = stringToPDFString(parentItem.get("T") || "");
    this.data.contents = stringToPDFString(parentItem.get("Contents") || "");
  }
}
class FreeTextAnnotation extends MarkupAnnotation {