Make `$test_nowarn_mod` available to downstream packages

[sloede]

          Can we somehow export this as well when importing TrixiBase from a testing environment? Then we can avoid duplicating this function from Trixi.

Originally posted by @efaulhaber in #5 (comment)

[ranocha]

My suggestion would be to call this macro @trixi_test_nowarn and include it in a package TrixiTest.jl.

[sloede]

Sounds good to me. I'd just like to gather some experience with (the additional management overhead of) TrixiBase.jl first, before adding more upstream packages.

However, if someone else is willing to set up TrixiTest.jl right now, I wouldn't be opposed either.

[JoshuaLampert]

Is it time to create a TrixiTest.jl? I now have three packages using a copy of @test_nowarn_mod. Together with Trixi.jl, TrixiShallowWater.jl, TrixiAtmo.jl, TrixiParticles.jl, PointNeighbors.jl, and TrixiBase.jl itself we have at least nine packages using copies of this function. Would be nice if they could use it from a TrixiTest.jl (or use a slightly modified version, which only adds some additional_ignore_content that's package-specific). I can start a package draft if you agree.
Then we can also discuss if we want to add any other functions or macros to TrixiTest.jl.

[ranocha]

That would be nice 👍

[JoshuaLampert]

Looks like I don't have the permission to create a repository for trixi-framework. Could maybe some of the principle developers of trixi-framework create the repo? I can create a PR then.

[ranocha]

https://github.com/trixi-framework/TrixiTest.jl