Fixed EZP-23043 DemoController topMenuAction should take into account la...

...nguages

This also fixes https://jira.ez.no/browse/EZP-23043. 

I did another pr for that https://github.com/ezsystems/DemoBundle/pull/100, but this other pr didn't take in account the work related to knpMenuBundle that is being done. 

Pull requesting here this as i think it will make the merge easier. I think we'd could get some conflicts if not..

ping @bdunogier