Fix write replay ordering when immediate_commit != all

Previous implementation didn't respect write ordering and could lead
to corrupted data when restarting writes after an OSD outage

Also rework cluster_client queueing logic and add tests for it to verify the correct behaviour

src/messenger.h

@@ -16,7 +16,7 @@
 #include "json11/json11.hpp"
 #include "msgr_op.h"
 #include "timerfd_manager.h"
-#include "ringloop.h"
+#include <ringloop.h>
 
 #define CL_READ_HDR 1
 #define CL_READ_DATA 2