Associate FIDO2 credential to account enrollment.

Endpoint to complete the registration of a FIDO2 credential by associating it to the account enrollment for Open Finance Brasil payment initiation. The enrollment must be in AWAITING_ENROLLMENT status. After successful registration, the enrollment transitions to AUTHORISED status. Failure to verify the FIDO2 credential causes enrollment rejection, as the same challenge cannot be reused for multiple registrations. This endpoint receives the response from the WebAuthn navigator.credentials.create() process executed on the user's device.