Enable fp8 support (#1101)

* initial checkin

* resolve cr comments

* resolve the build issue

* fix the data correctless issue

* update fp8 header file and update the unit test for fp8 support

* remove fp16 from fp8 headers

* fix ut issue and catch up the latest code from develop

* udate according to cr comments

* update ut according to cr comments

* update num floats for each SumPostDiv from 4 to 6

* update fp8 header file name

* fix the typo

[ROCm/rccl commit: 6777e65c1d]

projects/rccl/ext-net/example/nccl/types.h

@@ -16,6 +16,8 @@ typedef enum { ncclInt8       = 0, ncclChar       = 0,
                ncclFloat32    = 7, ncclFloat      = 7,
                ncclFloat64    = 8, ncclDouble     = 8,
                ncclBfloat16   = 9,
+               ncclFp8E4M3    = 10,
+               ncclFp8E5M2    = 11,
 } ncclDataType_t;
 
 #endif