UpdateIp4NetsComand -> UpdateIp4Nets, here and in filename.

I'd like it to be "data:ip4nets", for consistency with "data:countries". Or make update:countries, if you really prefer "update:" prefix. Also, I'm not sure how useful this would be but we could have php artisan data:ip4nets {ip} to see/test the resolution.

1. A nicer error handling when the request fails. Right now the only error I see is "Unable to display the estimated time if the maximum number of steps is not set.". What's more, it creates an empty file, so you cannot update it later.
2. In data:countries we don't use curl, file_get_contents/file_put_contents for consistency.

This should fix both:

if (!is_file($file)) {
    $content = file_get_contents($url); // This throws errors on failure
    if ($content) {
        file_put_contents($file, $content);
    }
}

What if there's no record found? What if country is unset? I don't see a fallback.

I think the net_ prefix is redundant for all of these columns. How about "network" instead of "net_number"? How about storing IPs as numbers? Our main select have to convert everything.