Add 'seen_entities' to Vitess

Goal

We should add 'seen_entities' to vitess in order to better query our clustered recommendations. Redis can only store the last 1 hour due to bandwidth constraints.

What needs to be done

One record per pseudo_id and entity_guid with a timestamp of last viewed.

QA

N/A

UX/Design

N/A

Personas

N/A

Experiments

N/A

Acceptance Criteria

• A new table in vitess
• Add 'seen_entities' to vitess, as we do with Redis.
• Consider using an EventStream for seen_entities and batching results into Vitess (scaling)
• Spec tests

Definition of Ready Checklist

• Definition Of Done (DoD)
• Acceptance criteria
• Weighted
• QA
• UX/Design
• Personas
• Experiments