FQDN support in Internet proxy configuration

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