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)



unreachable("Abstract method `AnnotationElement.render` called");
  }
  /**
   * @private
   * @returns {Array}
   */
  _getElementsByName(name, skipId = null) {
    const fields = [];
    if (this._fieldObjects) {
      const fieldObj = this._fieldObjects[name];
      if (fieldObj) {
        for (const { page, id, exportValues } of fieldObj) {
          if (page === -1) {
            continue;
          }
          if (id === skipId) {
            continue;
          }
          const exportValue =
            typeof exportValues === "string" ? exportValues : null;
          const domElement = document.getElementById(id);
          if (domElement && !GetElementsByNameSet.has(domElement)) {
            warn(`_getElementsByName - element not allowed: ${id}`);