[php-src] Issue #9807: Thread-safe alternatives to gettext/ngettext

Issue: https://github.com/php/php-src/issues/9807 Author: TysonAndre ### Description Motivation: If an application running on a web server uses gettext mo files for translations (e.g. for rendering a web page, or for generating translated strings to notify users that the logged in user interacted with), it would be prevented from using the ZTS (threaded) APIs (e.g. php-fpm+zts) It seems like /usr/include/libintl.h still doesn't have thread safe alternatives https://www.php.net/manual/en/function.ngettext.php https://www.gnu.org/software/gettext/manual/html_node/MO-Files.html documents the messages.mo format https://www.php.net/bindtextdomain > The bindtextdomain() information is maintained per process, not per thread. https://docs.laminas.dev/laminas-i18n/ user polyfills exist instead; should this be moved to pecl entirely?