IPv6

Is your feature request related to a problem? Please describe.

This issue is a meta-issue. When this issue will supported, I suggest to make a label "ipv6" and I will add new issues about it.

I think I needn't to explain the reason.
If you do new client, it should support ipv6.

Describe the solution you'd like
Implementing IPv6 it is really hard task. But it need to do.
I consider 3 different components

• Server
• Client
• Masterlist

Server: Need to turn on IPv6 on the socket, check functions(natives) which work with IP addresses, f.e bans must work by subnets (theoretically we can adaptive a native BlockIpAddress to 2001:db8:1:2:*:*:*:*, or make by standards 2001:db8:1:2::/64)
Client: Current classic client don't support it. So, new client and launcher must accept IPv6.
Masterlist: There need to rework a masterlist. Add new rows like fqdn. In that case, IP addresses must be an array, because we have v4 address + we can push few address of ipv6 (only global unicast 2000::/3), and yes if users have IPv6, AAAA records must be forced to them, like it happens in any modern OS or in software.

Describe alternatives you've considered
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Additional context
https://www.google.com/intl/en/ipv6/statistics.html
https://radar.cloudflare.com/adoption-and-usage

(Most of mobile operators have dominate percent by IPv6)

This is a meta-issue covering IPv6 support for the server, client, and masterlist. Start by mapping the networking entry points for those three components and reading how sockets, IP addresses, bans, and masterlist addresses are handled. Done would require an agreed implementation plan and IPv6 support across all listed components.