Provide full deployment capabilities for UD(A)F Functions.

[stewartbryson]

UDFs are currently deployed to KSQL servers by a simple copy of the JAR to a directory on the server, followed by a restart. Right now, the only thing this plugin does for deployment is to pull down the JAR dependency from a JAR repository and copy it to the build directory. This is because we used Jenkins to move the file into place for the project where the plugin was designed.

I'd like to go ahead and add remote copy capabilities. There a candidate plugins that may assist in this.

[stewartbryson]

Currently, this plugin builds and prepares artifacts for deployment, but in the project it was designed for, other mechanisms (Jenkins, Ansible) actually deliver artifacts for Streams and Functions to downstream environments. It would be nice to have functionality internal to the plugin to handle this.

KSQL artifacts already have deployment mechanisms using the KSQL REST API. But the deployment of Functions (UDFs and UDAFs) require an external process to deploy the artifacts. We just need a simple SSH-enabled copy pattern for this. gradlessh or groovyssh seem like good candidates.