Crosswalk Zenodo records to SDMX + CKAN

[khaeru]

Zenodo records contain metadata in a Zenodo-specific structure. This metadata can be adapted to (a) the TDC Metadata Structure (TDC-MS) and (b) to the structure specific to TDC CKAN.

To resolve, in one or more PRs:

1. Add a generic tool to fetch and adapt Zenodo (meta)data to SDMX. This can:
   • Cache the files from the Zenodo record locally.
   • Identify whether or not they contain SDMX (meta)data.
2. Add a generic tool to adapt SDMX metadata to CKAN metadata.
3. Add a higher-level tool that (a) does both (1) and (2) and (b) publishes both to a CKAN package + resources.