Expose icon and navbar aliases to SCI

[pfeodrippe]

Wdyt of exposing to SCI all the namespaces that the render-notebook :render-fn function uses?

With this, we would be able to copy it and modify it for our own needs, the missing namespaces at the moment are navbar, icon, and weirdly, the var viewer/css-class (even if I use the alias v) is not available for me, but this is minor.