Coding standards and safer shell argument processing

Address note from #7, and targetting the 2.x branch since that's the branch supporting D10 work.

Also addressed an (unintended change in behaviour with the Drupal 10 compatibility update

     // Return a new managed file object using the generated thumbnail.
-    return $image ? file_save_data($image, $sourceUri . '.png', FileSystemInterface::EXISTS_REPLACE) : NULL;
+    return $image ? \Drupal::service('file.repository')
+      ->writeData($image, $sourceUri . '.png') : NULL;
+

, FileSystemInterface::EXISTS_REPLACE is no longer passed through, which might lead to lots of _2.png type thumbnail files.

Reuploaded the latest MR as a patch for deployment purposes.

Thanks for your contribution. There's now a new stable release fixing the issues.

Automatically closed - issue fixed for 2 weeks with no activity.