[Onprem] Script for Automatic setup/launching for Onprem servers

[michaelzhiluo]

Should be tested after #1114 and #1116 are merged. This PR releases a script that automatically launches a cloud VM (acting as an onprem server) and sets up a regular user called test on the cloud server. It will also run sky admin deploy and setup the local cluster config as needed.

Example

python examples/local/launch_cloud_onprem.py -- local-cluster-name hello sky launch -c hello -- 'echo hi'

[michaelzhiluo]

@romilbhardwaj Just tested the script. It works as of now.

[michaelzhiluo]

@romilbhardwaj Done, think its ready to be merge 👍