[Feature Request] Support IPv6 for custom DNS server

[salixh5]

Feature request

Description

Currently when navigating to Settings > DNS and enabling the custom DNS server feature, the user has to use IPv4 as IP address for the server. Also, only a single IP can be set.

Describe the solution you'd like

I would like to be able to also use IPv6 addresses. Additionally, it would be great if we could use multiple IPs here.

Describe alternatives you've considered

The current setting works well as long as your DNS server is reachable over IPv4. The vast majority of public DNS servers support IPv4, so not adding this feature at all won't impact users of public DNS servers much.