Entity Management App. Update cached authorities/entities with external updates

Purpose:
The cached datasets will be updated by the dataset creators; as such, there needs to be a mechanism to update those datasets without losing the various connection points with other types of records (e.g.: bibliographic MARC records, etc.).

Use case:
As a metadata operations staff member, I need to update pref labels (e.g.: LCNAF records where a death date is added to a heading), and also manage merged authorities, split authorities and deleted authorities, for example. Authority and entity datasets are updated with varying frequencies. These external updates may or may not overwrite local updates/enhancements to those records in the local system.

Dependencies/Context:
Reliant on having completed "Cache external authorities/entities" (UXPROD-2516). Must account for "Add data points / enhance external authority/entity data" feature".

Notes from the Entity Management Working Group:
The extent of the update workflow should be defined further. I.e.: is there an automated process that goes out and pulls in updates for which authority? Is it all externally mediated? etc.