Spike: Listing favorites backend

[ludtkemorgan]

The only part of the favoriting feature from Detroit in core is the DB tables existing. The rest of the feature we need to figure out how we will consolidate it so that it still works and doesn't conflict with the rest of the features in core

• Should we keep the same db tables/fields that are there now
• How can we consolidate this in core
• New endpoints needed
• How would feature flags work for this