Function validateRawCustomer

Returns {
    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;
}