Attach (recommended) or Link to PDF file here:
[test planning.pdf](https://github.com/mozilla/pdf.js/files/7305078/test.planning.pdf)

Configuration:
- Web browser and its version: Firefox 93
- Operating system and its version: Windows 10 21H2
- PDF.js version: The integrated version
- Is a browser extension: no

Steps to reproduce the problem:
1. In the example, all shape and the "Line" cell of the first cell have a comment
2. Mouse over a "Line" cell or a shape, nothing appear except on mouse over their border
3. It is too difficult to use
4. There is also a vertical orientation issue reported in bug #7631

What is the expected behavior? (add screenshot)
Comments are shown on mouse hover or mouse click inside a cell or a shape

What went wrong? (add screenshot)
Comments are not shown when mouse hover or clicking inside a cell or a shape, only on their border

![image](https://user-images.githubusercontent.com/7791600/136419088-e083e2a3-d376-4d8c-9e0b-ce9dd5b83923.png)



container.style.borderWidth = `${data.borderStyle.width}px`;
      if (data.borderStyle.style !== AnnotationBorderStyleType.UNDERLINE) {
        
        
        
        width -= 2 * data.borderStyle.width;
        height -= 2 * data.borderStyle.width;
      }
      const horizontalRadius = data.borderStyle.horizontalCornerRadius;
      const verticalRadius = data.borderStyle.verticalCornerRadius;
      if (horizontalRadius > 0 || verticalRadius > 0) {
        const radius = `${horizontalRadius}px / ${verticalRadius}px`;
        container.style.borderRadius = radius;
      }
      switch (data.borderStyle.style) {
        case AnnotationBorderStyleType.SOLID:
          container.style.borderStyle = "solid";
          break;
        case AnnotationBorderStyleType.DASHED:
          container.style.borderStyle = "dashed";
          break;
        case AnnotationBorderStyleType.BEVELED:
          warn("Unimplemented border style: beveled");
          break;
        case AnnotationBorderStyleType.INSET:
          warn("Unimplemented border style: inset");
          break;
        case AnnotationBorderStyleType.UNDERLINE:
          container.style.borderBottomStyle = "solid";
          break;