Use `socket.AI_NUMERICHOST` ?

[vshymanskyy]

Currently, we check if hostname is numeric like this (_gai is the original socket.getaddrinfo):

if _ip4(host) or _ip6(host):
    return _gai(host, port, family, type, proto, flags)

We could completely remove _ip4 and _ip6 functions and use AI_NUMERICHOST which will reduce the code size by ~10%:

try:
    return _gai(host, port, family, type, proto, flags | socket.AI_NUMERICHOST)
except Exception:
    pass

This was tested with Python 3 and works fine.
However, AI_NUMERICHOST is currently is not exposed in MicroPython.
It does seem to be available in lwip so we could use it. It requires more testing.