Send 24h OSSEC alert if v2 onion services are enabled

[eloquence]

As part of the 1.7.0 release, we want to leverage OSSEC to remind admins of the importance of switching to v3 services. One way to do so is to send an alert every 24 hours if v2 services are configured. We could vary the message depending on whether v3 onion services are also enabled, using language identical or corresponding to that case in the Journalist Interface banner (#5672).

User Story

As an admin who works hard to keep my Monitor Server up and running, I like to see it earn its keep by sending me useful security reminders, so that I can act upon them when needed.