Migrate notebooks to the BeakerX (groovy) kernel, away from the Scijava kernel

All of the existing notebooks currently run on the [scijava-jupyter-kernel](https://github.com/scijava/scijava-jupyter-kernel), and there are a few issues that come with this:

* Many of the features added by the Scijava kernel were added to BeakerX (autotranslation/polyglot functionality, etc.)
* As time goes on we will have to maintain the Scijava kernel, updating it for new functionalities and new dependency versions. Considering the above point this work might prove unneeded and time-consuming.

Because of these issues @ctrueden and I decided to write all new notebooks in the [BeakerX](http://github.com/twosigma/beakerx) groovy kernel, and to slowly migrate the existing notebooks over as well.

Furthermore all new modifications required for our notebooks, such as displaying images side by side, can either be pushed to BeakerX, in which they will have larger community impact.