Moving status pages for older ROS 2 distributions

The ROS 2 repository status pages stored at had been getting very full, especially as our active distributions make their way down the alphabet. To surface the most useful information first, the final status pages for ROS distributions that are no longer active have been moved into an archive subdirectory.

Since the status pages only ever captured the latest status of each distribution, there is very limited value in actually retaining these final generated status pages so they may be deleted in the future.