Create cross-platform build script

The current build script (Scripts/buildpack.bat) only works on Windows, but not on MacOS.

In order to be able to build from the command line and create nuget packages also on MacOS, one could either:

• add a Mac-specific build script or
• create a cross-platform build script (maybe based on cake)

Option 2 is clearly preferable IMHO, but option 1 is still better than the current state of things.

[pauldendulk]

I also consider dropping support for things that can not be build cross platform, or move them to a separate github repository.

[janusw]

Not inclined to add Cake. Linux sh scripts are actually not that bad because they could also be built with WSL2 on Windows. I expect this to become a more common approach in general.

What’s your argument against cake?

The problem with shell scripts is that they are not 100% portable. First of all the shell on Mac is not exactly the same as on Linux/WSL (zsh vs bash), and then there are issues like file paths etc. I don’t have too much experience with cake, but I think it helps to abstract away such differences, so that one can really have a single cross-platform build script.

Eventually I would like to use more github actions and also release nugets through github actions.

I agree that it would make sense to use github actions for the CI builds. This also came to my mind, and it might help to work around #1115.