[YUNIKORN-2138] Implement a lightweight monitor tool

[wusamzong]

What is this PR for?

While existing [performance testing tools|https://github.com/apache/yunikorn-release/tree/master/perf-tools] are well-established, this test aimed to broaden the scope of test items to include diverse Kubernetes features such as Priority class, toleration, etc., which also involve stochasticity.
Consequently, there is a need to implement a lightweight throughput monitoring tool.

Todos

• - Task

What is the Jira issue?

https://issues.apache.org/jira/browse/YUNIKORN-2138/

How should this be tested?

Screenshots (if appropriate)

Questions:

• - The licenses files need update.
• - There is breaking changes for older versions.
• - It needs documentation.

[craigcondit]

I'm not sure I see the value in this. It seems like this tool just generates some (configurable) number of pods in a namespace and measures what.. cpu / memory usage of yunikorn? This is probably much better handled in some sort of integration test in the k8shim repo for one thing. Also, rather than generating pods directly (and not cleaning them up) it would be far better to just submit a Job with 'n' parallelism. Let's keep the release repo clear of these sorts of things. Closing this.