Refactor DCATUS writer to handle ISO1195-2, FGDC/CSDGM, and ISO19139

[rshewitt]

User Story

In order to successfully transform current spatial harvest sources (i.e. ISO1195-2, FGDC/CSDGM, and ISO19139 ), datagov wants refactor the DCATUS writer to handle all 3 source types.

Acceptance Criteria

[ACs should be clearly demoable/verifiable whenever possible. Try specifying them using BDD.]

• GIVEN the DCATUS writer
  AND the harvesting of ISO1195-2, FGDC/CSDGM, and ISO19139 source types
  WHEN any of those documents are read into mdtranslator
  THEN the information is transformed into DCATUS

Background

• the DCATUS writer is designed around ISO19115-3.
• the DCATUS writer needs to accommodate all 3 supported metadata types

Security Considerations (required)

[Any security concerns that might be implicated in the change. "None" is OK, just be explicit here!]

Sketch

• identify common information between all 3 types and determine where to read/write it in the internal metadata object

[rshewitt]

ISO19115-2/3, FGDC, and ISO19139 all support use-constraint information. we could refactor the dcatus rights module to return a concatenated string with just the use-constraints.