vyos.configdict(): T4228: is_member() must return member interface config dict
vyos.configdict(): T4228: is_member() must return member interface config dict

This extends commit 39157912 ("vyos.configdict(): T4228: is_member() must use
the "real" hardware interface") and returns the config dict of the used member
interfaces.

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x