gh-132742: Refactor fcntl.fcntl() and fcntl.ioctl() (GH-132768)
* Support arbitrary bytes-like objects, not only bytes, in fcntl().
* The fcntl() buffer argument is now null-terminated.
* Automatically retry an ioctl() system calls failing with EINTR.
* Release the GIL for an ioctl() system call even for large bytes-like object.
* Do not silence arbitrary errors whet try to get a buffer.
* Optimize argument parsing, check the argument type before trying to get
a buffer or convert it to integer.
* Fix some error messages.