Before implementing the metadata spec, we need to know where to implement it in; so we need to decide where to store it.
I see three options:
- in the main swh-storage, which may cause some issues scaling
- implemented in swh-storage, but running on a different postgres/cassandra cluster, which might be confusing
- implemented in a new component entirely, which adds some complexity and code duplication with swh-storage if we decide to use postgres or cassandra