Adjust helper to correctly use region. Create helper for thumbnail image

Hi Splendido.

Thanks for making this code sample.
I've made some adjustments to correctly use the region.
Also, I made a helper for the getting the thumbnail image directly from S3. I does add a new issue though, i.e. it's not reactive to the changes in S3. I expect the reactivity that you had going used the reactively of the upload and store into collectionFS. Unfortunately, I'm finding that there is a small delay between the event and them being available on S3, (Failed to load resource: the server responded with a status of 403 (Forbidden) ). When I go to s3 a moment later they are there and are available.