Create end to end demo to demonstrate linea on a real world use case

[saulshanabrook]

Opening this issue to keep track of where we are at for an end-to-end demo, and to record what first needs to be done to get there.

Dependencies:

• Run jupyter by default in notebooks
• Support re-running a notebook by default, by dealing with two artifacts same name, so that we can set the default linea DB to one on disk instead of memory

The others we could have if we want to do an airflow story is:

• SQL side effect UX
• Airflow UX in the notebook
• Test airflow UX in notebook

[saulshanabrook]

#368 fixes the first two

#385 does the SQL one

@yifanwu and I chatted about the prioritizing the last one today as well.

[saulshanabrook]

I am merging #391 #390 #388 #386 and #385 so that we can more easily have a working demo. I have tagged them all with "needs-review" to track that they should have a post hoc review, and create issues for follow ups.