Manage relationships between bundles / collections / products

[jordanpadams]

• Extract references from a Collection inventory file.

Acceptance criteria:
Given a bundle
When it is harvested and loaded in the registry
Then: the relationships between bundles - collections and observational products are stored in elasticSearch

[tdddblog]

• Finished implementation.
• Loaded some data (bundles, collections, observational products, spice kernels, docs, etc.) for InSight and OREX missions into Virtuoso on pds-dev3.

[tloubrieu-jpl]

The relationship from bundle to collections are stored in 'registry' index, in document in ref_lid_collection attribute.

The relationship from collections to observational products are stored in registry-refs index