FQDN support for Smart CLI source address configuration

NetBrain currently requires the Smart CLI source address to be entered as a static IP address, with no option to specify a fully qualified domain name. This enhancement would allow administrators to configure the Smart CLI source using an FQDN, which the system would resolve as needed for connections. Supporting FQDN would reduce maintenance overhead for customers whose source addresses change periodically, since the FQDN could remain constant while underlying IP assignments are updated independently.