deposit: Transit raw metadata to the loader to unify with metadata update scenario
The new update scenario now stores new metadata update to the metadata storage. The loader does not, it currently stores the transformed xml (into json dict). The loader passes by this deposit_read call to actually retrieve the data.
So prior to adapting the loader, the information returned by deposit_read need to provide the raw metadata as well.
This also:
- adds type to impacted methods along the way.
- simplifies a bit the current deposit_read tests
In D4101, I refactor this deposit_read endpoint and add some docs about it.
In D4105, I adapt the deposit loader to this new format change (so it sends that raw information in the metadata storage instead of the current transformed metadata)
Related to #2649 (closed)
Test Plan
tox
Migrated from D4100 (view on Phabricator)