CNB: netlink: add support for formatted extack messages

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2180938
Tested: Just build... no way to test, the commit just adds new macros

Commits:

51c352bdbcd2 ("netlink: add support for formatted extack messages")

Signed-off-by: Ivan Vecera ivecera@redhat.com