Add common build tool

[secana]

This PR adds just as a command runner and a nix development shell with all tools installed. This allows for easy build, test and release of all SDKs without the need to search through the code how each individual SDK is built. It works on all Linux and macOS (Unix) platforms, where Nix is supported.

This should significantly reduce the friction for contributing to the project and provides a documentation to build and test the SDKs in code.

ATTENTION:
The release-* commands are untested, as I didn't want to release a bunch of SDKs to test the commands. If you release a new SDK version, please check if the command works and fix it if not.

I fumbled with the C++ and Ruby environment variable handling for the tests. It could be possible that the CI pipeline breaks and the SDKs need a fix, as I couldn't test that before.

[unglaublicherdude]

I appreciate the work and it looks like a good Idea to have a possbillity to build all the projects with one tool.

I personally still go with the devcontainers I think, because the devcontainer environments do more than this, they also provide syntax highlighting, auto-complete, a test-explorer, debugging and you can use the remote containers functionality where it basically behaves as you run it locally but it actually runs on some remote system. That's really important for me, doing work from a rather slow internet connection.

[GermanCoding]

Very cool!

[GermanCoding]

We should also consider enabling Nix support for renovate (https://docs.renovatebot.com/modules/manager/nix/) and probably also consider enabling https://docs.renovatebot.com/configuration-options/#lockfilemaintenance such that the flake.lock gets updated from time to time.

[unglaublicherdude]

We should also consider enabling Nix support for renovate (https://docs.renovatebot.com/modules/manager/nix/) and probably also consider enabling https://docs.renovatebot.com/configuration-options/#lockfilemaintenance such that the flake.lock gets updated from time to time.

I just added a commit, that does that.

[unglaublicherdude]

Wouldn't it be cool, to also use those tasks in the ci? It would make sure, they always work.

[secana]

I appreciate the work and it looks like a good Idea to have a possbillity to build all the projects with one tool.

I personally still go with the devcontainers I think, because the devcontainer environments do more than this, they also provide syntax highlighting, auto-complete, a test-explorer, debugging and you can use the remote containers functionality where it basically behaves as you run it locally but it actually runs on some remote system. That's really important for me, doing work from a rather slow internet connection.

You can add any IDE. GUI or terminal, to the flake.nix with a corresponding config. But I didn't want to provide an IDE but a simple tool to test all SDKs with one command in the case that there is a change in the backend. As I don't know all of the languages well, it was hard for me to remember how to build and release new versions of the SDK.