When Cell Input of a `using/import` cell is hidden, installation progress is invisible.

[pankgeorg]

That leads to situations where a notebook might be loading for quite some time and the user has no feedback to understand what is going on.

A solution to that can be a more centralized status update screen that lets the user know what is going on, which cell is running and for how long. In case of installation (which always happens first, according to pluto topology order, we can additionally show the Pkg Popup content.)