download jenkins-cli.jar instead of extracting it from jenkins.war

[hoomaan-kh]

… the Jenkins-cli.

https://github.com/voxpupuli/puppet-jenkins/issues/998

Pull Request (PR) description

This Pull Request (PR) fixes the following issues

[ekohl]

This has a merge conflict. Could you make sure it cleanly applies?

[hoomaan-kh]

The conflict had been fixed

[kenyon]

For reference, the docs for this are here: https://www.jenkins.io/doc/book/managing/cli/#downloading-the-client

[hoomaan-kh]

Do we need more changes or it could be merged?

[kenyon]

Do we need more changes or it could be merged?

We need the tests to pass. I rebased on latest master and squashed the commits.

[ekohl]

The current solution does work and there hasn't been activity for a year. Closing, but feel free to open a new PR.