move MGW endpoint FSM from osmo-bsc to here

Move mgw_endpoint_fsm from osmo-bsc here as osmo_mgcpc_ep_fsm. Apply various
renames for consistency. Use osmo_tdef from libosmocore instead of osmo-bsc's
(so far) local T_defs API.

Change T23042 to T2427001, which is a slightly less arbitrary number and
slightly more extendable in the future (2427 corresponds to the default MGCP
port at osmo-mgw, 001 is the first MGCP timer and so far the only one).

Change-Id: I9a3effd38e72841529df6c135c077116981dea36
diff --git a/include/osmocom/mgcp_client/mgcp_client_fsm.h b/include/osmocom/mgcp_client/mgcp_client_fsm.h
index dabfcca..e170a25 100644
--- a/include/osmocom/mgcp_client/mgcp_client_fsm.h
+++ b/include/osmocom/mgcp_client/mgcp_client_fsm.h
@@ -64,3 +64,5 @@
 void mgcp_conn_delete(struct osmo_fsm_inst *fi);
 
 const char *mgcp_conn_get_ci(struct osmo_fsm_inst *fi);
+
+const char *osmo_mgcpc_conn_peer_name(const struct mgcp_conn_peer *info);