To understand how databrickslabs_jupyterlab works, let's fist look at how Standard Jupyter kernels get started
Databrickslabs_jupyterlab intercepts step 3, creates two sets of communication ports and forwards the local ports to the remote machine. The orange boxes and arrows are databrickslabs_jupyterlab specific, the others are standard actions and components
On the remote machine, the call dbcontext() creates a Databricks execution context and connects via this context to the Spark Context
Finally, since there is a network connection between Jupyter and the kernel and since clusters can auto terminte, the local ssh tunnel gets monitored and the result transferred to Juyopter frontend
