Use JDK from metadata if possible

[jonesbusy]

This also simplify the PluginModernizer flow

• We don't compile the plugin if we don't have metadata
• Create local metadata or get them from cache if present
• We run the recipe
• We verify the plugin (including tests)

Testing done

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[jonesbusy]

This was way too complicated for so little benefit