update indexer for storage 0.0.156

this imply a refactoring of the db schema for origin_intrinsic_metadata, since
we do not have nor want numerical ids for origins, we use origin urls instead.

Note that IndexerStorage.origin_intrinsic_metadata_search_by_producer() still
have start/end arguments which are expected to be strings, thus uses
lexicographic comparisons between origin urls. This is far from
ideal, but a proper fix requires an (new?) endpoint that handle pagination
properly.