Include and Use onion XMPP servers by default

coy IM includes and uses services with onion services out of the box. It would be a nice enhancement for Tor Messenger to have IMHO.

"Probably worth pointing out that @coyproject preferentially uses onion addresses if known, here's the list built-in: https://github.com/twstrike/coyim/blob/master/servers/known.go#L18"