[shadow-validation] stripe/refund: UCS↔HS request diff

Shadow-validation flagged a connector-request diff for **stripe / refund**. `header.keyDiff.stripe-account={"hyperswitch":true,"ucs":false} | body.keyDiff.charge={"hyperswitch":true,"ucs":false} | body.keyDiff.payment_intent={"hyperswitch":false,"ucs":true} | body.keyDiff.refund_application_fee={"hyperswitch":true,"ucs":false}` Fixed by UCS PR #1552.