add gRPC-haskell benchmark (fixed)

[4eUeP]

Summary of changes

Bench gRPC-haskell. (Prior: #243)

Finally, the fixed pr awakesecurity/gRPC-haskell#140 was merged.

Run on my local machine:

$ ./bench.sh haskell_grpc_haskell_bench 

-----------------------------------------------------------------------------------------------------------------------------------------
| name                        |   req/s |   avg. latency |        90 % in |        95 % in |        99 % in | avg. cpu |   avg. memory |
-----------------------------------------------------------------------------------------------------------------------------------------
| haskell_grpc_haskell        |   10544 |       88.72 ms |      102.18 ms |      107.94 ms |      201.48 ms |    64.6% |     126.5 MiB |
-----------------------------------------------------------------------------------------------------------------------------------------

[LesnyRumcajs]

Fantastic. How about dropping the current Haskell implementation that is on hold?

[4eUeP]

@LesnyRumcajs Yes, I agree with dropping it because the mu-haskell seems to be not maintained.

[LesnyRumcajs]

Thank you!