Improve language dropdown menu

[cory2067]

This is pretty gross. Instead, we should have these options change based on which tourney is currently being viewed.

The code for this is in Navbar.js, where there's a hardcoded list of language options.
Maybe we could populate the list of available languages based off what files are in the client/src/content directory

[Briesmas]

I'd like to add something to this.
Change the "Language" on the top menu to a more recognizable term/icon by everyone. Some ppl don't seem to know this word. I believe either displaying the current selected language (English, ...) or a flag (like osu! website) would make it clearer.