ref(logs): implement __destruct to make sure logs are always flushed

[Litarnus]

This PR updates the LogsHandler to extent \Monolog\Handler\Handler so that we inherit the __destruct method which will flush when being destructed.

Implements __destruct manually to make sure that logs are always flushed once the handler is destructed.
This will make sure that no logs are lost in case calling flush() is forgotten.

We cannot use \Monolog\Handler\Handler because it is not available for the lowest version of monolog we support.

resolves #1915
closes PHP-33

[linear]

PHP-33 LogsHandler should call close() on __desctuct().