Attach (recommended) or Link to PDF file here:
[Testfile v1.5 to PDFA2.pdf](https://github.com/mozilla/pdf.js/files/6310752/Testfile.v1.5.to.PDFA2.pdf)


Configuration:
- Web browser and its version: Version 89.0.4389.114 (Offizieller Build) (x86_64)
- Operating system and its version: Windows 10 / MacOS BigSur
- PDF.js version: 2.5.207
- Is a browser extension: no 

Steps to reproduce the problem:
1.  Open Testfile v1.5 to PDFA2.pdf in pdf.js viewer demo
2. text is covered up by markings / highlights which are stored in pdf itself

What is the expected behavior? (add screenshot)
Should be displayed as in Acrobat Reader
<img width="1169" alt="Bildschirmfoto 2021-04-14 um 14 24 41" src="https://user-images.githubusercontent.com/1286150/114710202-bf175a80-9d2d-11eb-8d54-75481fe91b7d.png">

What went wrong? (add screenshot)
It's how it is displayed in pdf.js viewer
<img width="782" alt="Bildschirmfoto 2021-04-14 um 14 24 16" src="https://user-images.githubusercontent.com/1286150/114710311-d8200b80-9d2d-11eb-8000-b67b94488929.png">

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

this.color = getRgbColor(color);
  }
  /**
   * Set the border style (as AnnotationBorderStyle object).
   *
   * @public
   * @memberof Annotation
   * @param {Dict} borderStyle - The border style dictionary
   */
  setBorderStyle(borderStyle) {
    if (
      typeof PDFJSDev === "undefined" ||
      PDFJSDev.test("!PRODUCTION || TESTING")
    ) {
      assert(this.rectangle, "setRectangle must have been called previously.");
    }
    this.borderStyle = new AnnotationBorderStyle();
    if (!isDict(borderStyle)) {
      return;
    }
    if (borderStyle.has("BS")) {
      const dict = borderStyle.get("BS");
      const dictType = dict.get("Type");
      if (!dictType || isName(dictType, "Border")) {
        this.borderStyle.setWidth(dict.get("W"), this.rectangle);
        this.borderStyle.setStyle(dict.get("S"));