v0.0.172 * Unify exception raised by invalid input to API endpoints. * Add a validation proxy for _add() methods. This proxy is *required* in front of all backends whose _add() methods may be called or they'll crash at runtime. * Fix RecursionError when storage proxies are deepcopied or unpickled. * storages: Refactor objstorage operations with a dedicated collaborator * storages: Refactor journal operations with a dedicated writer collab