Allow a remote file to be specified for the Source path parameter

A patch rolled from #5 ✨ Allow a remote file to be specified for the Source path parameter Active .

Taking inspiration from patch #15 → of ✨ Import data from URL Closed: won't fix , with a fix to for the removal of file_save_data() → , it may be simpler to replace all the curl bits to go with something like:

    // Retrieve data from URL.
    $data = file_get_contents($remote_path);
    if ($data === FALSE) {
      throw new \RuntimeException("Unable to retrieve data from '{$remote_path}'.");
    }
    // Save data to temporary dir.
    $path = "temporary://" . basename($remote_path);
    $file = \Drupal::service('file.repository')->writeData($data, $path);
    if ($file === FALSE) {
      throw new \RuntimeException("Unable to save file to '{$path}'.");
    }
    return $file->getFileUri();

jcandan → changed the visibility of the branch 3469594-allow-a-remote to hidden.

We have Guzzle available to us so the curl isn't really needed.

Also, I'm not sure I like the idea of having remote resources download-able by default with this module. That opens up the attack surface quite a bit. Being able to do any prep work for a resource could/should happen before the migration happens. Say via a shell script that curl/downloads the resources locally first. Convince me why this is strictly necessary.