Function validateRawCustomers

Returns {
    users: {
        user_birthday: null | string;
        user_city: null | string;
        user_company: null | string;
        user_country: null | string;
        user_custom_fields?: any;
        user_email: null | string;
        user_firstname: null | string;
        user_houseNumber: null | string;
        user_id: number;
        user_notes: null | string;
        user_phoneNumber: null | string;
        user_postalCode: null | string;
        user_salutation: null | string;
        user_street: null | string;
        user_surname: null | string;
        user_timestamp: null | string;
        user_uidNumber: null | string;
    }[];
}