Expose --jupyter on the scheduler

[jacobtomlinson]

If you set --jupyter on the dask scheduler command it will start Jupyter on the same web server as the dashboard. This PR exposes that option easily via KubeCluster and the dask kubernetes gen CLI.

from dask_kubernetes.operator import KubeCluster

# NOTE: The image must have Jupyter installed
cluster = KubeCluster(name="dask-jupyter", image="ghcr.io/dask/dask-notebook:latest", jupyter=True)

# You can quickly get the Jupyter link with
print(cluster.jupyter_link)

This is also with with dask kubernetes gen cluster.

$ dask kubernetes gen cluster --name dask-jupyter --image ghcr.io/dask/dask-notebook:latest --jupyter

And the link is listed in the dask kubernetes port-forward output.

$ dask kubernetes port-forward dask-jupyter
Scheduler at: tcp://localhost:50457
Dashboard at: http://localhost:62546/status
Jupyter at: http://localhost:62546/jupyter/lab
Press ctrl+c to exit