Add support for DDNS modification

[davwheat]

The Hub 3 secretly has DDNS capabilities with several common providers.

To see and edit these settings, log in to the admin page, then open devtools. Go to Application, then Session Storage and replace the disable and hide keys' values with ;;. This will unlock all hidden settings to the user, including the DDNS functionality, which works correctly.

More interestingly, this shows new IPv6 info on the Admin > Info page, too.