Add cron job to run characterEditStats.php on multilingual wikis weekly

Publishes the output a wiki page on Meta.  Needs a MediaWiki install (with
Translate), hence on terbium. Inspired partly by misc/beta/sync-site-resources
and files/icinga/check_job_queue.

Bug: 58440
Change-Id: I681539b6cf2463648d4c5669d689143c2f41cc33