mdns/bonjour/zeroconf support

[bonesoul]

https://github.com/lathiat/avahi
https://github.com/sbp/tweetnacl-tools

best candicates:
https://github.com/richardschneider/net-mdns
https://github.com/tomasmcguinness/dotnet-mdns
https://tomasmcguinness.com/2018/01/22/apple-bonjour-for-net-core/
https://tomasmcguinness.com/2018/01/26/apple-bonjour-for-net-core-part-2/
https://tomasmcguinness.com/2018/01/29/apple-bonjour-for-net-core-part-3/

others
https://github.com/novotnyllc/Zeroconf
https://github.com/arkane-systems/Arkane.Zeroconf
https://github.com/PingmanTools/Zeroconf
https://github.com/mono/Mono.Zeroconf
https://archive.codeplex.com/?p=zeroconf
https://www.mono-project.com/archived/monozeroconf/
https://github.com/mono/Mono.Zeroconf/blob/master/src/MZClient/ZeroconfClient.cs