So the only changes I made are:
- added selType: 'cellmodel' to grid config
- added a select listener that will show a pop-up with the selected cell coordinates when the select event is fired.
- the alert pop-up should be showed only when a cell is clicked/selected
- if a cell was clicked, pressing on one of the table headers to sort the data will trigger the select event and the pop-up will be displayed. Example: click on the first cell: a pop-up with 'cell at position 0 | 0 was selected' will be showed. Then click on 'Email' header to sort the grid, and again the same pop-up will be showed. After that the cell is deselected.