Allow environment to control custom connects to backend

[pankgeorg]

• A new PlutoEvent 🎉 to notify interested parties about when an evaluation cycle is done!
• Small refactor around BinderLaunch button so it's logic is not too convoluted in the Editor.js
• Ability to provide custom launch button if some server also provides a static 🌟✨ 'environment'🌟✨ javascript!
• When an event goes all wrong, stop @warn ing all the event (the notebook can easily cause the logging system to crash, e.g. if you're watching and serving the logs over HTTP)

[github-actions[bot]]

Try this Pull Request!

Open Julia and type:

julia> import Pkg
julia> Pkg.activate(temp=true)
julia> Pkg.add(url="https://github.com/fonsp/Pluto.jl", rev="pg/more-backends")
julia> using Pluto

[fonsp]

can you fix the big diff? did you intend to change the package lock?

[pankgeorg]

can you fix the big diff? did you intend to change the package lock?

I actually did, to support the next version (16/lts vs 14?) of node if I remember correctly. But since, I couldn't make the bundle work for our usecase so I reverted the update!

[fonsp]

I looked over the code so far, ✅ code looks great, I just want to run this code locally (without the extension) to make sure that the Run Local / Run Binder buttons still work

[fonsp]

You can merge yourself after addressing/dismissing those comments ✅