Move event.h into ipc_lib

Makes tab completion a lot less annoying.

Change-Id: I0c905ba112c274d23b5f0277b9a5c2a8e4e238f6
diff --git a/aos/network/message_bridge_test.cc b/aos/network/message_bridge_test.cc
index a9e918b..ca5bcb8 100644
--- a/aos/network/message_bridge_test.cc
+++ b/aos/network/message_bridge_test.cc
@@ -1,16 +1,15 @@
-#include "gtest/gtest.h"
-
 #include <chrono>
 #include <thread>
 
 #include "absl/strings/str_cat.h"
-#include "aos/event.h"
 #include "aos/events/ping_generated.h"
 #include "aos/events/pong_generated.h"
+#include "aos/ipc_lib/event.h"
 #include "aos/network/message_bridge_client_lib.h"
 #include "aos/network/message_bridge_server_lib.h"
 #include "aos/network/team_number.h"
 #include "aos/util/file.h"
+#include "gtest/gtest.h"
 
 namespace aos {
 void SetShmBase(const std::string_view base);