[LEBV-100] Add footer

🎯 Summary

Add footer with links that change depending on the selected language:

🧪 How to test

Change the language and check that the language changes

🧠 Considerations

I have used the German texts as default because I don't want to use Google Translate and these tests will be reviewed anyway before sending them to Lebara.

🧐 Checklist

Changes work in Google Chrome
Changes work in Safari
UI is responsive