Analyze hash kv API performance

[gyuho]

Create >1GB db file and measure how long it takes to get hash kvs.
This is critical for data corruption checking.

ref. #8554

[gyuho]

/cc @spzala

[spzala]

We are creating a benchmark put sub-command for this under #9866 Below is a snippet of few related examples output,

HaskKV Summary:
  HashKV: 1407003244
  Endpoint: http://127.0.0.1:2379
  Time taken to get hashkv: 917.035345ms
  DB size: 1.1 GB

HaskKV Summary:
  HashKV: 1286658187
  Endpoint: http://127.0.0.1:2379
  Time taken to get hashkv: 1.609064019s
  DB size: 2.1 GB

HaskKV Summary:
  HashKV: 4280873459
  Endpoint: http://127.0.0.1:2379
  Time taken to get hashkv: 4.971754313s
  DB size: 8.3 GB