[FE] 10-10EZR: Make only one NoK on FE

[alexseelig]

User Story

As a Veteran, I want to be able to update my NoK online so that VA knows who to contact if something happens to me.

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Acceptance Criteria/Definition of Done

• Reference updated EC/NoK designs
• Set Array Builder to max of 1 NoK so we only have one NoK for the Veteran to view and update
• For delete, pass flag to backend
• Success: We have one one NoK for Veterans to update/delete in STG/RI

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Resources

• Design links
• Screenshots
• Reference docs/tickets where we have this kind of work documented
• Etc.