refactor: move transport (etcp/stcp/normalizer) to transport_layer/, routing (bgp/pings/topo*) to routing_layer/

tests/test_nat_engine.c

@@ -13,7 +13,7 @@
 #include <string.h>
 #include "../lib/debug_config.h"
 #include "../src/eim_nat.h"
-#include "../src/etcp.h"
+#include "etcp.h"
 #include "../src/config_parser.h"
 
 #ifdef ENABLE_STATIC_ASSERT