Refactor notebook rendering to backend

[jezdez]

Currently we render the Jupyter notebook contents and the Zeppelin notebook contents via frontend libraries (notebookjs and remarkable). The downside is that we lose context and the ability to use native UI elements of the actual Jupyter and Zeppelin interfaces.

Instead we should move to bridging the gaps to the actual backend services to be able to see the notebooks rendered correctly. This would get rid of the frontend libraries.

As to how to achieve this a few options come to mind:

• proxying the backend's http interfaces, rewriting the URLs etc..
• using a 3rd party or dedicated hosted version where we upload the notebooks just for rendering
• frames/iframes etc to some of the above
• using Jupyter/Zeppelin APIs to render the notebooks on the webheads in-place

[rafrombrc]

Initial task on this is to spend a couple of hours of exploratory work deciding which (if any) of the listed approaches makes the most sense.

[washort]

What exactly are we looking for that the current solution doesn't provide? Would something like nbviewer do the job?