Added Unit test for nccl send recv (#506)

Added Send Receive test that tests through all pairs

[ROCm/rccl commit: ff54e79799]

projects/rccl/test/common/PrepDataFuncs.hpp

@@ -22,5 +22,6 @@ namespace RcclUnitTesting
   ErrCode DefaultPrepData_ReduceScatter(CollectiveArgs &collArgs);
   ErrCode DefaultPrepData_Scatter(CollectiveArgs &collArgs);
   ErrCode DefaultPrepData_AllToAll(CollectiveArgs &collArgs);
-  ErrCode DefaultPrepData_SendRecv(CollectiveArgs &collArgs);
+  ErrCode DefaultPrepData_Send(CollectiveArgs &collArgs);
+  ErrCode DefaultPrepData_Recv(CollectiveArgs &collArgs);
 }