This function has a bug when `last` returns npos (which then fails an
assertion in a debug build).
Rather than fixing it, it seemed easier just to remove it and rely on
the split() version that does almost exactly the same thing but takes a
string_view delimiter.
* make it so that we don't set up unbound resolver when we have no resolvers provided by config
* clean up dns codepath and make it use llarp::SockAddr instead of llarp::IpAddress
- Make SockAddr endian arguments explicit
- Consolidate port-less contructors and port constructors into one with
a default port of 0.
- Add {h,n}uint128_t ctors for construction from IPv6 addrs
* rework net code for ip ranges to be cleaner
* clean up endpoint auth code
* refactor config to validate network configs before setting up endpoints
* remove buildone from path/pathbuilder.cpp so we don't spam connection attempts
- Move IPRange into its own net/ip_range.hpp
- Move the static net::IPPacket::TruncateV6, etc. functions to free
net::TruncateV6, etc. functions (now from net/ip.hpp instead of
net/ip_packet.hpp).
- Make net::TruncateV6 and net::ExpandV4 constexpr.
- Add IPRange::FromIPv4 factory function (to replace the iprange_ipv4
free function)
