The concept of a Serve Application, a data structure containing all information needed to deploy Serve on a Ray cluster, has surfaced during recent design discussions. This change introduces a formal Application data structure and refactors existing code to use it.
When the script terminates, it will also terminate its cluster including dashboard, which will prevent subsequent job submissions. Other long running e2e tests do not terminate in smoke test mode, so make `serve_failure` behave the same.
Now that `HeadOnly` becomes the new default HTTP location, we can
re-enable the long running tests to use local multi-clusters.
(also fixed the controller's API to match up to date, we should
have caught these, I will open issues for this.)
