Attach (recommended) or Link to PDF file here:
[output.pdf](https://github.com/mozilla/pdf.js/files/6374987/output.pdf)

Configuration:
- Web browser and its version: Firefox 88.0
- Operating system and its version: macOS Big Sur 11.2.3 (20D91)
- PDF.js version: 2.8.243
- Is a browser extension: no/Firefox built-in

Steps to reproduce the problem:
1.  add Ink-Annotations to a pdf (i use https://github.com/highkite/pdfAnnotate, Annotations with appearance streams are shown correctly)
2. open output file in firefox

What is the expected behavior? 
The annotations should be visible.
![Bildschirmfoto 2021-04-26 um 09 15 48](https://user-images.githubusercontent.com/33630884/116043809-6a020f80-a670-11eb-973c-6f2df3dae532.png)

What went wrong? 
The annotations are added to the dom but invisible.
![Bildschirmfoto 2021-04-26 um 09 18 26](https://user-images.githubusercontent.com/33630884/116043867-7e460c80-a670-11eb-964d-0cc2c6dbfb61.png)

Tested successfull with FoxitReader, AcrobatReader, Chrome and Safari.
constructor(parameters) {
    super(parameters);
    this.data.annotationType = AnnotationType.INK;
    this.data.inkLists = [];
    const rawInkLists = parameters.dict.getArray("InkList");
    if (!Array.isArray(rawInkLists)) {
      return;
    }
    const xref = parameters.xref;
    for (let i = 0, ii = rawInkLists.length; i < ii; ++i) {
      /
      /
      /
      /
      this.data.inkLists.push([]);
      for (let j = 0, jj = rawInkLists[i].length; j < jj; j += 2) {
        this.data.inkLists[i].push({
          x: xref.fetchIfRef(rawInkLists[i][j]),
          y: xref.fetchIfRef(rawInkLists[i][j + 1]),
        });
      }
    }
  }
}
class HighlightAnnotation extends MarkupAnnotation {
  constructor(parameters) {
    super(parameters);
    this.data.annotationType = AnnotationType.HIGHLIGHT;
    const quadPoints = (this.data.quadPoints = getQuadPoints(