Improve representation of Registrar data schema

The "Qualities of Registrar Data" document (current working title) contains a table showing what data is proposed to be supplied by Registrars for the GRID.

If/when the GRID becomes operational, we will want this schema to be used by participant Registrars (eligible, applied, etc. etc.) for the data that they make available.

It would be better if the data was described in a way that was machine readable to enable automated tests of compliance before publication/harvesting.

In addition, a machine readable expression can also be used in our Pilot implementation to as part of the verification process for harvested pilot data. The code used by the GRID to verify the harvested data format conformance can also be used by Pilot participants prior to publication.