testing: Add expect-connection calls for all tests and hosts

There are some exceptions (e.g. those that use auto=start or p2pnat).

testing/tests/ikev2/ip-two-pools-v4v6-db/pretest.dat

@@ -5,5 +5,6 @@ moon::ipsec pool --add v6_pool --start fec3:\:1 --end fec3:\:fe --timeout  48 2>
 alice::ip -6 route add default via fec1:\:1
 moon::ipsec start
 carol::ipsec start
+moon::expect-connection rw
 carol::expect-connection home
 carol::ipsec up home