[META] Introduce Aggregate Command

[OVI3D0]

META issue for issues related to this RFC: #627

Issues based off priorities from RFC:

• Add Ability to aggregate results across multiple OSB test executions: [Introduce Aggregate Command] Add Ability to aggregate results across multiple OSB test executions #629
• Enhance Compare command to be able to compare aggregated results from two or more test executions: [Introduce Aggregate Subcommand] Enhance opensearch-benchmark compare command #630
• Incorporate automatic aggregation into new and existing features: [Introduce Aggregate Command] Incorporate Automatic Aggregation #631
• Store Aggregated results in a separate local folder [FEATURE] Store Aggregated test results in a separate local folder #661
• Add relative standard deviation (RSD) to the new aggregate feature [FEATURE] Add relative standard deviation (RSD) to the new aggregate feature #662
• Add support for custom iteration values [FEATURE] Support custom iteration values in new aggregate command #670
• Add median values and adjust min/max values [FEATURE] Add median values to aggregated test results and adjust min/max values #684

[IanHoang]

@OVI3D0 Can you create a few more tasks and add them to this META issue?

• Support storing results in MDS Add aggregate command #638 (comment)
• Store aggregations in separate local folder (such as ~/.benchmark/benchmarks/aggregations) Add aggregate command #638 (comment)
• Add RSD to aggregation test execution JSON add automatic testing and aggregation to OSB #655 (comment)