Create a top-level Attribution element in Structured Content Schema.

This demands a bulk ingestion for the structured contents service (different ticket)

TO DO

• Finalise decision if we duplicate the last edit time data in the object
• Create an Attribution Object with the following
  • editor - threshold number - whatever makes the least number of calls for us
    • anonymous_count
    • registered_count
  • parsed_references_count
  • last_revised
    • as MM/YY - no day or time
• Update structured content schema with Attribution object

• Update unit tests
• Document additions (data dictionary, Json shema, etc.)

QA

• Unit test passes
• Shema changes doesn't break anything