[php-src] PR #23997: IO hooks PoC

Pull Request: https://github.com/php/php-src/pull/23997 Author: bukka This is a proof of concept for IO hooks and contains working implementation for Polling API additions, IO Hooks and IO Ring API as defined in the following RFC's: * Polling API additions: https://wiki.php.net/rfc/poll_api_additions * IO Hooks: https://wiki.php.net/rfc/io_hooks * IO Ring: https://wiki.php.net/rfc/io_ring It was important to design and implement all 3 together to make sure all need functionality is covered. The detailed living design can be seen at https://gist.github.com/bukka/87359261a4bfaa572ce43c93c0554b55 (it is updated at date of creation of this PR but as this is draft it might get slightly out of sync but the implementation should always cover what is in the actual RFC's). It should be noted that this also depends on #22538 that is pre-requisite for this and integrated to this PoC. Once merged, this will get rebased. This is not supposed to be reviewes as it is and it will stay as a draft. Instead smaller PR's will be introduced for the actual review. This is more as a reference and CI check.