[FEATURE] Add new benchmark function for single operator comparison

[agrabows]

Description

This change is about adding new compare operators functionality to MXNet Operator Performance Benchmarks and also enable existing functions to run mx.np/mx.npx operators.

Checklist

Essentials

• PR's title starts with a category (e.g. [BUGFIX], [MODEL], [TUTORIAL], [FEATURE], [DOC], etc)
• Changes are complete (i.e. I finished coding on this PR)
• Code is well-documented

Changes

• Modified existing function for mx.nd module operators benchmarking to be able to run mx.np/mx.npx operators.
• Added function allowing comparison of operators between modules
• Updated README file

[mxnet-bot]

Hey @agrabows , Thanks for submitting the PR
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[agrabows]

@mxnet-bot run ci [unix-cpu]

[mxnet-bot]

Jenkins CI successfully triggered : [unix-cpu]

[agrabows]

@mxnet-bot run ci [windows-gpu]

[mxnet-bot]

Jenkins CI successfully triggered : [windows-gpu]