Migrate user collections from old solr to new solr

[theorm]

• RK: export collections from old solr
• ME: re-import collection in new solr

Export format, best would be to package things by title-year jsonl.bz2 files, if possible

| actionfem-1927.jsonl.bz2
| actionfem-1928.jsonl.bz2

And the dump could look like (or similar):

{ci_id1: xxx, collection_ids: [xx, yy, zz]}
{ci_id2: xxx, collection_ids: [xx, yy, zz]}

[e-maud]

Documentation of steps:

# untar the dump
tar -xvjf collections_prod_dump.tar.bz2

# reorganise folders
$ cd collection_prod_dump
$ for file in *.jsonl; do title=$(echo "$file" | cut -d'-' -f1); mkdir -p "$title"; mv "$file" "$title/"; bzip2 "$title/$file"; done

# upload on s3
s3cmd put --recursive --dry-run collections_prod_dump/ s3://42-processed-data-final/solr-user-collections/solr-user-collections-prod/