Add Aqua, UndocumentedNames and ExplicitImports checks

[j-fu]

Use the new tooling based on public and the ExplicitImports in order to identify use of non-public names from Julia and other packages. Once they are identified, one can discuss with the maintainers:

• Make them public so they are marked as stable API?
• Add some stable wrapper API around internals ?
• Create a shim package separating the dependencies on internals (see https://discourse.julialang.org/t/i-find-it-hard-to-develop-in-julia/135497/58)?
• Get some ideas what could replace the use of internals ?

I think this can be done for Pluto, but needs to start from the helper packages in the PlutoJL org.

I could make corresponding PRs like JuliaPluto/ExpressionExplorer.jl#31 (once we agree upon this).

This may help to move on from https://discourse.julialang.org/t/i-find-it-hard-to-develop-in-julia/135497

[Pangoraw]

While this might help, if we take the case of ExpressionExplorer.jl for example, I think the case where it can break because of a new release are more subtle.

It relies on the Expr struct which has no stable API since a new form or new lowering can be introduced at any version (not saying it is a bad thing). As such, there will be maintenance work whenever a new form is introduced. "Recent" examples include

• named tuple unwrapping (; a, b, c) = d
• try / catch / else

[j-fu]

Well, I see ExpressionExplorer as a companion package of Pluto, I guess they are essentially developed in parallel by very much the same persons. I am quite sure ExplicitImports has a way to make an exception for this package.

The approach I am thinking about has been described very well in this post later on in the discourse thread mentioned above.

While I generally would be able (and like to) take part in this endeavour, I will be tight with time during the next couple of weeks.