[feature] Assign a context recommendation to a context owner

[ClaireGz]

Problem

Context recommendations currently have no owner. There is no way to assign or attribute a given recommendation to a specific context owner (the person responsible for that domain/context), so recos are not routed to whoever should action them and ownership can't be tracked.

Expected behavior

Allow each context recommendation to be assigned/attributed to a context owner, so that:

• recommendations are routed to the responsible owner
• ownership and follow-through can be tracked per owner

Customer ID

537eff89-4a62-4f5d-ae4e-0b5d2b25fb8a

[ClaireGz]

Companion issue for the share-link half of this ask: #1574 (share/copy a direct link to a recommendation). This issue stays scoped to assignment/ownership.