rename socket.h/cpp to shm_socket.h/cpp.

lichao

2021-05-20 4ad4f24f18cf7d0af22ca885baebc6a3eb37e7d0

 src/exported_symbols

@@ -5,6 +5,7 @@
   BHUnregister;
   BHRegisterTopics;
   BHQueryTopicAddress;
   BHQueryProcs;
   BHSubscribeTopics;
   BHStartWorker;
   BHHeartbeatEasy;