Portraits jupyter (#597)

* added demo jupyter notebook

* first clickable example

* update for Peter

* cleraner

* all elements are here, we just need to clean it up

* uncommented out js stuff

* ran the whole thing should appear now

* add exception if requesting too many subcells

* extras and axes labels example

* updated notebook

* updated nb

* Adds an example to generate a portrait plot with modal support

* add reusable func

* minor change: title location to be middle of upper margin

* clean up merge notebook for further improvement and showing merge later

* updated JsonClass

* fixed portraits plot notebook AND portrait plots

* fix flake8