public void createOrUpdateItem(final String key, final Object value, final String comment) {
        this.createOrUpdateItem(key, GsonUtils.getInstance().toJson(value), comment);
    }
create or update item into namespace.
@param key item key
@param value item value
@param comment item comment
shenyu-admin-listener/shenyu-admin-listener-apollo/src/main/java/org/apache/shenyu/admin/listener/apollo/ApolloClient.java