indexer_storage: Publish indexer computation to journal topics
This allows going straight from loading an origin up to indexing in elasticsearch's index origin loaded.
Related to T2817 Related to T2590
Test Plan
$ doco -f docker-compose.yml -f docker-compose.search.yml -f docker-compose.override.yml up -d`
$ doco -f docker-compose.yml -f docker-compose.search.yml -f docker-compose.override.yml exec swh-loader swh loader run https://github.com/codemeta/codemeta
$ http://localhost:9200/_cat/indices?v
health status index uuid pri rep docs.count docs.deleted store.size pri.store.size
yellow open origin 44iUHZqWST-QoE5eOA39oQ 1 1 13 5 65.1kb 65.1kb
# There is elasticsearch "document" in the "origin" index
Migrated from D4709 (view on Phabricator)