RCCL Replayer update (#1603)

RCCL recorder w/ suggested change and UT

test/common/RcclMockFuncs.hpp

@@ -0,0 +1,7 @@
+#include "info.h"
+#include "comm.h"
+
+void ncclDebugLog(ncclDebugLogLevel, unsigned long, char const*, int, char const*, ...) {};
+ncclResult_t getHostName(char* hostname, int maxlen, const char delim) {
+  return ncclSuccess;
+}