Let agent collect and store IP addresses of application servers

HAWKULAR-488 orders that IP addresses should be displayed for Application servers. Citing pilhuhn:

For the IP, it would be the one where the http(s) interfaces are bound to. That can be found via interfaces and socket-binding-groups (and is unfortunately not entirely trivial)
<socket-binding-group default-interface="public" ...
<socket-binding name="http" port="$
{jboss.http.port:8080}