mysql client should understand -4 and -6 arguments to restrict hostname to IPv4 or IPv6

Lots of client utilities have `-4` and `-6` command line arguments that can be use to restrict address family considered when looking up a hostname.

mariadb client utilities should have them too.

This is especially useful when testing authentication (explicitly try IPv4 or IPv6), but also when for some other reason only one of the stacks should be preferred/used.