Collapse multiline if statements by adopting Laravel's abort_if and throw_if helpers.

Before

if ($failed) {
    abort(422, 'Validation failed');
}
 
if (!isset($parameter)) {
    throw new \InvalidArgumentException('Missing required parameter');
}

After

abort_if($failed, 422, 'Validation failed');
 
throw_if(!isset($parameter), new \InvalidArgumentException('Missing required parameter'));