03205a8955
Audit language names against BCP 47 validator and rename those which are not valid BCP 47 codes, leaving the old aliases for backward-compatibility. Validated against IANA registry at https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry with the help of the validator at http://schneegans.de/lv/ Add fully-expanded aliases for zh-XX language codes to help compatibility with other BCP 47 users. See also: https://github.com/wikimedia/mediawiki/blob/1113b1203cbc1049fb1d01e975ff9a531d72a408/languages/LanguageCode.php#L56