[th/ipaddr-order] ip: add test for checking order of IP addresses
The order of addresses is important. In the connection profile,
manual addresses have a defined order (see man nm-settings
about ipv4.addresses and ipv6.addresses). It gets more complicated,
because NetworkManager's current behavior differs depending on the
address family.
Add a test for the chosen order of IP addresses. We probably have a similar test already. Now there is another one.