[GIT-PULLS] [php-src] PR #22823: streams: check class exists when attempting to register stream filter

Pull Request: https://github.com/php/php-src/pull/22823
Author: Girgias

And do a few other checks such as is the class even instantiable. It might make sense in the future to raise a deprecation if the class does not extend php_user_filter or create a new StreamFilter interface so that we know the various methods exist