The 'No language found' placeholder did not exist (#635). The component
looked up account.change_language_details.no_currency_found, which is
not defined in the language sub-tree, so the picker rendered the raw
i18n key when a search filter matched nothing.
Switch the lookup to account.change_language_details.no_language_found
and add the matching English string. Other locales pick this key up
through the existing Weblate flow.
Closes #635
Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>