Include Approval Settings in commissionOverrides expand

Extend the /v1/affiliates/{id}?expand=commissionOverrides response to also include the affiliate’s approval configuration, such as approval type, approval settings, and hold period.

Use Case:
Users already fetch affiliate-specific commission configuration via commissionOverrides and need the related approval and holding logic in the same response to mirror program behavior correctly in their backend.

Expected Behavior:
When using ?expand=commissionOverrides, the response should also include fields like:

• approval_type

• hold_period

Notes:
This keeps all relevant commission-related configuration in one place and avoids requiring users to manually duplicate these settings externally.