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 type = this.data.combo ? "combobox" : "listbox";
    const value =
      this.data.fieldValue.length > 0 ? this.data.fieldValue[0] : null;
    return {
      id: this.data.id,
      value,
      defaultValue: this.data.defaultFieldValue,
      editable: !this.data.readOnly,
      name: this.data.fieldName,
      rect: this.data.rect,
      numItems: this.data.fieldValue.length,
      multipleSelection: this.data.multiSelect,
      hidden: this.data.hidden,
      actions: this.data.actions,
      items: this.data.options,
      page: this.data.pageIndex,
      type,
    };
  }
}
class SignatureWidgetAnnotation extends WidgetAnnotation {