kraken-build/: feature: Add kraken.build module which allows importing the current context and project from a build script as if calling Context.current() or Project.current()

[NiklasRosenstein]

We already have this functionality in kraken-hs but it has two drawbacks:

• It's only in kraken-hs, so no use for OSS projects!
• That implementation uses a lazy object proxy, which can cause issues down the line when passing the object to other functions (the proxy will always defer to the current project, not the project that the object was used in and passed somewhere else)