feat(presenter): make i18n locale extractable from url

[Elweyn]

🍰 Pullrequest

Issues

• None

Todo

• None

[ulfgebhardt]

This looks very good. Please check if you can unify the language defintions so that it wold be easier to add new languages.
If this is a big overhead which prevents merging, we can merge it and have a new task for that.

[ulfgebhardt]

I can only use http://localhost:3000/en/impressum but not http://localhost:3000/de/impressum which I expected to be able.
Since de is the default language this should not imply a change for the page, still I think every valid language should be acceptable as the language parameter.

In general this is the right approach it just needs to be finished properly to be production ready.
There is a problem resulting from the manual language switch, which might be subject of another PR:
When you are on http://localhost:3000/en/impressum and select de in the menu the URL does not change, which then sets the content unaligned with the given url - so assume the following user flow:

• User goes to page
• Wants to send link to friend
• Notices - oh friend only speaks german
• Switches language
• Sends link

-> This scenario falls short here.

[ulfgebhardt]

A further test revealed that page navigation loses the locale.

If you are on http://localhost:3000/en/impressum and navigate to http://localhost:3000/ locale is de again. This is actually an regression from previous functionality where the locale set in the browser was preserved.