Create a openfoodfacts-query for producers data

[alexgarel]

• specific to *.pro.openfoodfacts.org
• it must have the owner-tags as an important data
• we have to setup a redisstream for it
• product opener must filter on owner-tag for normal users (and let moderators access all)

[john-gom]

Note that owners_tags is already included in off-query. e.g.
curl -d '[{"$match":{}},{"$group":{"_id":"$owners_tags"}}]' -H "Content-Type: application/json" https://query.openfoodfacts.org/aggregate

[alexgarel]

@john-gom the idea here would be to be able:

1. to use off-query to compute facets for producers data
2. to also have events on this platform.