Remove "primary" field from Contact

Problem/Motivation

The primary base field on the Contact entity type is an entity reference to another Contact. There is no context for what a Contact's "primary" Contact represents. Relationships allow Contacts to be linked with additional context about the relationship.

Proposed resolution

• Remove the "primary" field from the Contact entity type
• Possibly create a follow-up issue to add a reference to a Contact's primary Relationship

Remaining tasks

User interface changes

API changes

Data model changes