Get STUN/TURN usage statistics from ejabberdctl

Is your feature request related to a problem? Please describe.
At this time, there is no way to get stats or usage statistics from ejabberdctl about STUN/TURN features.

Describe the solution you'd like
It would be good (I think) that one could retrieve information similar to what one can retrieve with XMPP, on the use of STUN/TURN, with ejabberdctl commands, such as (but not limited to) total/average data relayed, average link duration, per user stats, etc

Describe alternatives you've considered
The only way to do something related is to change the log verbosity to 'info' and grep "Offering STUN/TURN" or "Relayed" to obtain some incomplete infos.

Additional context
I am co-administrator of the chapril.org XMPP server, which is open to the public, and we recently configured the server to support audio/video calls.

Thank you very much,
Regards

Start by reviewing the ejabberdctl command entry points and the existing STUN/TURN logging mentioned in the issue. Define which statistics are required, including relayed data, link duration, and per-user usage, and how the commands should expose them; the work is done when the agreed metrics can be retrieved without relying on log grepping.