Component: Language switcher

[Yolijn]

@Robbert Jeffrey and I would like to brainstorm about this component further before adding it to the index (again).

Thoughts:

• link for url-changes
• button for content-changes
• what about switching when many languages are available?
• what about the google-translate options Den Haag is currently thinking about?

[Yolijn]

We gaan in plaats language-navigation-as-button gebruiken https://github.com/nl-design-system/backlog/issues/243