[gradle] Added JavaLauncher capability to agent run

[MartelliEnrico]

This is a first implementation of the javaLauncher support for agent run and metadataCopy task.

I'm still having issues with local testing, since it's not really explained how to handle the multiple version of java required by the plugin. Also the agent run tests are failing when run from the functionalTest project, but if replicated by hand they are working fine (if setting the default java sdk to a graalvm one).

I'm more than thankful if someone can help me with the tests situation 😄

Fixes #724

[oracle-contributor-agreement]

Thank you for your pull request and welcome to our community! To contribute, please sign the Oracle Contributor Agreement (OCA).
The following contributors of this PR have not signed the OCA:

• PR author: MartelliEnrico
• mrcnrt95e30@gmail.com (@MartelliEnrico)

To sign the OCA, please create an Oracle account and sign the OCA in Oracle's Contributor Agreement Application.

When signing the OCA, please provide your GitHub username. After signing the OCA and getting an OCA approval from Oracle, this PR will be automatically updated.

If you are an Oracle employee, please make sure that you are a member of the main Oracle GitHub organization, and your membership in this organization is public.

[oracle-contributor-agreement]

Thank you for signing the OCA.

[melix]

Thanks for the pull request @MartelliEnrico , I'll take a look. The requirements for testing will be simpler once #725 is merged.