Separate or remove JVM-specific features

Some features of Blue-Base cannot be used when compiling to JavaScript, and might also not compile to assembly when Kotlin Native is released. These should be removed, or at least brought into a separate repository.

Start by inventorying the JVM-specific features in Blue-Base and checking which parts fail when compiling to JavaScript. Determine whether each feature should be removed or moved into a separate repository; the work is done when the remaining project is compatible with its supported targets and the JVM-only features have been separated or removed.

Written by the indexing model from the issue text.