🐡 Better error message when package fails to load

[fonsp]

Changes:

• stderr content from the precompilation process is captured and displayed in the Pkg log. It used to only show in the terminal that launched Pluto.
• A new error rewriter in the frontend that detects the standard error message and replaces it with something more useful, also displaying a copy of the Pkg terminal with the error mesage for that package. This also hides the advice to Pkg.add the package which is wrong and would lead to problems.
• The "precompile" status entry now shows in red if the precomp process failed

Before

After

[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="better-package-load-error")
  julia> using Pluto