Enabling and displaying ROOT JS Graphics and GUI Elements in JupyterLab

The document is split up into two parts. The first goal was to enable JSROOT graphics in JupyterLab, which requires the jsroot on command. These graphics should be displayed in the same way as in the old Jupyter Notebooks with all their interactive features. In this second part the goal was to integrate ROOT JS GUI such as the TBrowser (new: RBrowser) or the FitPanel as native elements in JupyterLab.