Dynamically populate BF Refs when retrieving a Resource

[jermnelson]

When retrieving a resource from the API, dynamically query MongoDB to populate some of the following bfAdminMetadataRefs,
bfItemRefs, bfInstanceRefs, and bfWorksRefs fields with the corresponding resource URIs.

For a bf:Instance:

• Populate bfWorksRefs with BF Work URLs from the bf:Instance resource's bf:instanceOf triples. We should also query MongoDB for the inverse property of any bf:Works that have bf:hasInstance properties with the bf:Instance's URL.
• Populate bfItemRefs with BF Item URLs from the bf:Instance resource's bf:hasItem triples. We should also query MongoDB for the inverse property of any bf:Items that have bf:itemOf properties with the bf:Instance's URL
• Populate bfAdminMetadataRefs with BF AdminMetadataRefs URLs from the bf:Instance resource's bf:adminMetadata resources. There is not a corresponding inverse property.

For a bf:Work

• Populate bfInstanceRefs with the BF Instance URLs from the bf:Work resource's bf:hasInstance triples. We should also query MongoDB for the inverse property of any bf:instanceOf that have bf:instanceOf properties with the bf:Work resource URL.
• Populate bfAdminMetadataRefs with BF AdminMetadataRefs URLs from the bf:Work resource's bf:adminMetadata resources. There is not a corresponding inverse property.

For a bf:Item

• Populate bfInstanceRefs with the BF Instance URLs from the bf:Item resource's bf:itemOf triples. We should also query MongoDB for the inverse property of any bf:Instances that have bf:hasItem properties with the bf:Item resource URL.