Finish the indexer -> swh-search pipeline

I wrote swh/devel/swh-indexer!195 (closed) and swh/devel/swh-journal!74 (closed) a year ago, they need to be rebased and merge so we can really use swh-search for the archive search in swh-web.

Migrated from T2590 (view on Phabricator)

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