Create ISO19115-1 reader in MDTranslator

[rshewitt]

User Story

In order to continue supporting ISO19115-1 documents for harvesting, datagov wants to create an ISO19115-1 reader in mdtranslator

Acceptance Criteria

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

• GIVEN that ISO19115-2 is a superset of ISO19115-1
  AND the existing ISO19115-2 reader
  WHEN a ISO19115-1 document is read into mdtranslator
  THEN it is transformed into dcatus
  [AND optionally another verifiable outcome]

Background

• dependent on #4846. once the -2 mapping is finalized work on this ticket.
• the feature branch noted below was created prior to updates from the human QA of the mappings so it might be good to start from scratch just to be safe. regardless, use that feature branch to see how it would be done.
• related to #4862
• feature branch

Security Considerations (required)

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

Sketch

• ISO19115-2 is a superset of ISO19115-1. the only difference is the root node namespace so this is basically a copy-paste.