Add Study fields to data model

[lopierra]

See red text here: https://docs.google.com/spreadsheets/d/1vDdcqt3Lgehyq1iCnlF1H9JZi63pLj-u/edit#gid=446601587&range=5:21

[putmantime]

Post march review of Study fields.
Needs to be revisited with Portal team

[lopierra]

UPDATE: New Study/Dataset fields to be added are here

Hold until DMC has finished filling out templates and resolved ongoing issues

[lopierra]

Part of #159