Reflect changes to Hecuba.
Include base/return types again.

Changed the timestamp to be a string type to allow for schema generation. But it still needs to be a valid timestamp for posting data.
Updated optional data.
Added dates back to schema.

Updated schema generation code meaning that generation of dates is possible.
Minor fix in Device metadata.
Added profile schemas.
Change id tags to snake_case.
Merge pull request #1 from MastodonC/feature/update-hecuba-schemas

Reflect changes to Hecuba.