charon-tkm: Adapt to interface changes to support multiple key exchanges

Also includes ESA flags.

Co-authored-by: Tobias Brunner <[email protected]>

testing/tests/tkm/xfrmproxy-expire/hosts/moon/etc/strongswan.conf.in

@@ -3,7 +3,7 @@
 charon-tkm {
   # remove rekeyed inbound SA a bit quicker for the test scenario
   delete_rekeyed_delay = 2
-  dh_mapping {
+  ke_mapping {
     15 = 1
     16 = 2
   }