Copy language command

__Tasks:__

- [x] test coverage
- [ ] gather feedback for my changes

__Informations:__

| Q             | A
| ------------- | ---
| Tests pass?   | yes
| Fixed tickets | part of https://github.com/sulu-cmf/sulu-standard/issues/125
| BC Breaks     | none
| Doc           | none
Because we need it today, and Dan introduced a new class in another PR, where this should be integrated.

And after the refactoring this logic should be in the node anyway.