fix(dns): Dynamic DNS sorting (RFC 6724) to work in IPv6-only network

This fix adds an option to dynamically set the order of DNS results based on
RFC 6724, to return the best destination address based on the available
source addresses, allowing a device with both IPv4 and IPv6 enabled to work
in any network configuration, including IPv4-only, IPv6-only, and dual-stack.

Without the option there is a static ordering preferring IPv4, which means
on an IPv6-only network, a dual-stack destination returns the IPv4 address,
which fails. Setting the static preference to IPv6 would have the opposite
problem. A dynamic sort, based on available source addresses, is required
to work on all networks.

Author: sgryphon