[Spreadsheet] fix tooltip to show newline instead of \n characters
[Spreadsheet] fix tooltip to show newline instead of \n characters

Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master