KVM : Align UserConsentStatus semantics for OptIn NotStarted state (spec + implementation)

[amarnath-ac]

Align KVM consent state semantics so OptInState NotStarted is no longer reported as Requested, preventing false pending-consent behavior for clients.

Scope:

1. Define the intended API representation for pre-request consent state (for example NotStarted/Required or nullable field).
2. Update backend mapping logic to distinguish NotStarted from Requested and Displayed.
3. Update API/OpenAPI contract and generated artifacts to match the new state model.
4. Update unit and integration tests for all consent-state transitions.
5. Validate runtime output on a real CCM-activated system.

Acceptance criteria:

1. When OptInState is NotStarted, UserConsentStatus is not Requested.
2. Requested and Displayed continue to map to the pending-request semantics only.
3. API contract clearly documents each consent state and transition intent.
4. Tests cover NotStarted, Requested, Displayed, Received, InSession, Denied, and Timeout.
5. Build, lint, and test pipelines pass with no regressions.