WebUI: Allow one IPv4 and one IPv6 address per Local DNS entry

[Docker Tag 2026.07.2 Core v6.4.3 FTL v6.7 Web interface v6.6]

I did not find a similar FR, though I found some work arounds/tricks.

Quite simply, I have two entries for all of my locally-hosted services and it would be simpler if the web UI could parse one IPv4 and one IPv6 into two valid entries into the backend rather than having to double each of them.

so instead of

a.fqdn.com    aaaa:ipv6:addr:1::2
a.fqdn.com    192.168.0.2
⋮
z.fqdn.com    aaaa:ipv6:addr:1::2
z.fqdn.com    192.168.0.2

agree upon delimiters, e.g., , and/or ; and/or | and that simplifies to

a.fqdn.com    aaaa:ipv6:addr:1::2, 192.168.0.2
⋮
z.fqdn.com    aaaa:ipv6:addr:1::2, 192.168.0.2