Run Rest Integ Tests with the Security plugin installed

[cwperks]

Description

Opening up a Draft PR to start soliciting feedback. The goal of this PR is to run integ tests in this repo with the security plugin installed. This PR is a step towards being able to add tests for https://github.com/opensearch-project/job-scheduler/pull/347.

With the change in this PR you can run the sample-extension-plugin with security using ./gradlew :opensearch-job-scheduler-sample-extension:run -Dsecurity=true -Dhttps=true -Dtests.opensearch.username=admin -Dtests.opensearch.password=admin -x integTest

And run integTest with security like:

./gradlew :opensearch-job-scheduler-sample-extension:integTest -Dsecurity=true -Dhttps=true -Dtests.opensearch.username=admin -Dtests.opensearch.password=admin -Duser=admin -Dpassword=admin -Dtests.opensearch.secure=true -i --tests "*RestIT"

Example response to CAT plugins

> curl -XGET https://admin:admin@localhost:9200/_cat/plugins -k
integTest-0 opensearch-job-scheduler                  3.0.0.0-SNAPSHOT
integTest-0 opensearch-job-scheduler-sample-extension 3.0.0.0-SNAPSHOT
integTest-0 opensearch-security                       3.0.0.0-SNAPSHOT

Check List

• [X] New functionality includes testing.
  • [X] All tests pass
• [X] New functionality has been documented.
  • [X] New functionality has javadoc added
• [X] Commits are signed per the DCO using --signoff

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[cwperks]

@prudhvigodithi I switched this to ready for review to start soliciting feedback, but I am still working on a change to remove duplication between the SPI and the sample-extension-plugin which both perform integ tests and have some classes in common. I was able to create a separate sourceSet with common test classes, but had some trouble bundling the resources like the certificates.