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/pretest.dat

@@ -4,6 +4,8 @@ alice::iptables-restore < /etc/iptables.rules
 moon::ipsec start
 carol::ipsec start
 alice::ipsec start
+moon::expect-connection int
+moon::expect-connection ext
 carol::expect-connection home
 carol::ipsec up home
 alice::expect-connection home