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)



const [selStart, selEnd] = event.detail.selRange;
              if (selStart >= 0 && selEnd < event.target.value.length) {
                event.target.setSelectionRange(selStart, selEnd);
              }
            },
          };
          this._dispatchEventFromSandbox(actions, jsEvent);
        });
        
        
        element.addEventListener("keydown", event => {
          elementData.beforeInputValue = event.target.value;
          
          
          let commitKey = -1;
          if (event.key === "Escape") {
            commitKey = 0;
          } else if (event.key === "Enter") {
            commitKey = 2;
          } else if (event.key === "Tab") {
            commitKey = 3;
          }
          if (commitKey === -1) {
            return;