Local Carbonado Retention

We should try to retain Carbonado-encoded files within the client, and provide them to methods that can make use of them. Then, automerge both sources of data, the local data and remote data. To do this, we'll need to return the actual Carbonado data in the web functions in addition to the response. This should help reduce data inconsistencies within the wallet as users make use of it.

- [ ] Modify methods that store Carbonado files to also return the Carbonado data
- [ ] Modify methods that retrieve Carbonado files to also accept Carbonado data and automerge with it