[FEATURE]PPL commands micro-benchmark support

[YANG-DB]

Is your feature request related to a problem?
Add support for micro-benchmark for each PPL command to examine the following KPI's:

• performance in several size and volume strategies
• detect performance regression in future code changes
• allow better execution analysis of complex queries

What solution would you like?
In a similar way to @LantaoJin comment there should be a correspondent micro-benchmark for every PPL command that can be testes independently

Do you have any additional context?

• Translate PPL dedup Command Part 2: allowedDuplication>1 #543 (comment)

[dai-chen]

FYI, Spark microbenchmark example: #291

[YANG-DB]

@dai-chen thanks for the info - I wanted to raise this issue to actually create a discussion about adding such benchmark for each PPL command - I'll add this to a new contributing.md doc...