Handle an 'akonadi did something' notification in KDE, etc.
    
    This handles a case where KDE shows a notification saying
    'PIM Maintenance (Finished)', like this:
    
    https://openqa.fedoraproject.org/tests/477345#step/desktop_notifications/34
    
    we need to click it away for the desktop_notification test to
    pass. It also clarifies the difference between this notification
    and the eternal 'akonadi_migration_agent is doing something'
    popup in the needle names and comments. It also replaces the
    'check_screen then assert_and_click if found' pattern in several
    notifications-related places with the better 'check_screen then
    click_lastmatch if found' pattern now available upstream.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>