Aggregate the JS and JVM projects to simplify builds.

Currently, commands such as `compile` and `publish` do not propagate to the JS and JVM projects, requiring separate `fooJS/compile` and 'fooJVM/compile` etc commands. By making the top-level project aggregate the JS and JVM projects, such commands now automatically propagate to the subproject.

By naming the root and subprojects the same, it also avoids publishing an empty jar (foo-root-project) when `publish` is invoked at the root project. Instead, now it correctly delivers `foo` and `foo_sjs` jars.