LDEV-988: Made the GroupingAction page handle both doing a grouping and going back to the screen later via the progress bar. To do this I had to make change performGrouping so it checks if the grouping has been done before trying to do it. Also changed the completeActivity to move the logic that closes the popup window to completeActivity rather than completeToolSession - now it is called for system tools like grouping as well as the normal tools.
