Add "Restart?" dialog on changing game locale

[Hares]

What?

Add option to restart the game after changing the locale, similar to mods list / mods settings.

Why?

1. It's inconsistent with the other game-breaking settings
2. It's annoying to restart manually

Why do I need change my locale?

1. I prefer playing the game on my native locale (most of the time)
2. If I need to send a bug report (which I do quite a lot), I switch to English locale so I can take screenshots