`:en` is English for both `standard_locale_name` and
`native_locale_name`, and so makes for a poor test candidate for
differentiating between them.

* Remove language detection through cld3

* Update app/helpers/languages_helper.rb

Co-authored-by: Yamagishi Kazutoshi <ykzts@desire.sh>

Co-authored-by: Yamagishi Kazutoshi <ykzts@desire.sh>

* Add trending links

* Add overriding specific links trendability

* Add link type to preview cards and only trend articles

Change trends review notifications from being sent every 5 minutes to being sent every 2 hours

Change threshold from 5 unique accounts to 15 unique accounts

* Fix tests

* Fix language filter codes

CLD3 returns BCP-47 language identifier, filter settings expect
identifiers in the ISO 639-1 format. Convert between formats,
and exclude duplicate languages from filter choices (zh-CN->zh)

* Fix zh name

* Add failing spec showing that human_locales does not match what i18n knows about

* Add missing `ar` key for arabic to human locales

* Remove duplicate `id` key from available locales

* Sort keys in human locales list

* Add spec for human_locale helper