testing: Add sql/shunt-policies-nat-rw scenario

testing/tests/sql/shunt-policies-nat-rw/hosts/venus/etc/strongswan.conf

@@ -0,0 +1,12 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+charon {
+  plugins {
+    sql {
+      database = sqlite:///etc/ipsec.d/ipsec.db
+    }
+  }
+  load = curl aes des sha1 sha2 md5 pem pkcs1 gmp random nonce x509 revocation hmac stroke kernel-netlink socket-default updown sqlite sql
+
+  keep_alive = 5
+}