Support the Visual Editor also for standard script files

[albertomercurio]

Description

Quarto already supports rendering standard script files like .py or .jl, by simply dividing the cells with # %%. However, it would be very nice if also the Visual Editor could support such files. In this way, I can still work with a pure .py file, but in a visual way, by rendering markdown and Latex equations for example. And when I need to run this file elsewhere (e.g., a cluster), the .py file is ready to use.

I find the Visual Editor very game-changing (although it doesn't support autocompletion and Copilot yet), and the support to also standard script file would be awesome.