Feeds output should be consistent with View active topic fields and ordering

As discussed in https://www.phpbb.com/community/viewtopic.php?f=466&t=2323986 it would be an improvement if there was consistency in the output (fields and order) of View active topics and the equivalent Atom feed (feed.php?mode=topics_active).

View active topics lists: <Subject> <username> <date> <forum name>

while the Atom feed lists: <forum name> <Subject> <username> <date>