`DefaultLocale` is too coarse-grained

[anthonyvdotbe]

While I find DefaultLocale helpful for methods like String::toUpperCase, I find it's an annoyance for methods like String::formatted and String::format. (Note that the former doesn't even have an overload that takes a Locale.) Also, when locale-agnostic is the typical case, it's better to do Locale.setDefault(Locale.Category.FORMAT, Locale.ROOT) and specify an explicit Locale in the exceptional case.