Fix batch upload in chunk cleanup whn in cluster without affinity

The batch upload in chunk creates a temporary file when building the final blob.
There is logic to keep the tmp file path in the transient store, for later deletion, but the cleanup of this tmp file cannot work in cluster without node affinity:
https://github.com/nuxeo/nuxeo-lts/blob/2021/modules/platform/nuxeo-automation/nuxeo-automation-server/src/main/java/org/nuxeo/ecm/automation/server/jaxrs/batch/BatchFileEntry.java#L229
https://github.com/nuxeo/nuxeo-lts/blob/2021/modules/platform/nuxeo-automation/nuxeo-automation-server/src/main/java/org/nuxeo/ecm/automation/server/jaxrs/batch/BatchFileEntry.java#L294

It would be better to store the final blob in the transient store too to let it handle the cleanup (and remove the tmp file right after build).