- internal nullptr checks
- prevent modifications to network_address (shallow copy issues)
- automagically works with any type containing interface functions
- removed fnv1a hashing
- ipv4_network_address now flattened with no base class
- Performance improvements
- Added `span` for zero-copy pointer+length arguments
- Added `std::ostream` overload for direct writing to output buffers
- Removal of unused `string_tools::buff_to_hex`