Propose to add system test for openjdk startup features

## Summary
Java is(or 'was') not suitable for shot lived applications, and is notorious for slow startup and performance hiccups during warmup.
There is some features in openjdk that could speed up startup and reduce memory footprint, I propose we add a system test to ensure these features did improve applications as expected.

Again this test will set a minimal bar for feature's optimization effect rather than benchmarking between different implementations.(The passed/failed is the final result instead of detailed start-up time).
> For example we assert [AppCDS](https://wiki.openjdk.java.net/display/HotSpot/Application+Class+Data+Sharing+-+AppCDS) improves at least 5% for some workload.

## What to include now
- [AppCDS](https://wiki.openjdk.java.net/display/HotSpot/Application+Class+Data+Sharing+-+AppCDS)
- [JarIndex](https://docs.oracle.com/javase/7/docs/technotes/guides/jar/jar.html#JAR_Index)

## What is new
> Now we have jtreg tests to ensure they are working separately.
This system test will add test in aspects as `does AppCDS work with JarIndex` and `some feature did bring improvements in real application`

I am trying in https://github.com/joeyleeeeeee97/aqa-systemtest/tree/serverless/openjdk.test.serverless/doc.
Looking forward to your feedback.

Start by reviewing the proposed work in the serverless/openjdk.test.serverless/doc branch and the linked AppCDS and JarIndex references. Define the system-test scope and workload before implementing it; done means the test covers the proposed feature interactions and reports whether the stated startup or memory improvement threshold is met.

Written by the indexing model from the issue text.