string.gsub returns two variables, the updated string and the pattern occurrences.
The outer string.gsub would replace n occurrences, or nothing if the string did not
contain '%'.
BREAKING CHANGE (kind of)
Remove user-selection for locales. Adds mostly unnecessary complexity,
and most people don't want to bother with it anyway.
Locale is always based on the convar "ox:locale" instead.
Partial, and google translated just for the sake of setting an example.
Also renamed many of the language codes where the extra characters are
redundant (i.e. fr-FR, de-DE).
