<!-- If you need to report a security issue please visit https://github.com/apache/dubbo/security/policy -->

- [ ] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.

## Describe the proposal
<!-- Please use this for a concrete design proposal for functionality. -->
<!-- If you just want to request a new feature and discuss the possible business value, create a Feature Request. -->

EN:
Observability task, optimizing thread pool index embedding function
1 Need to specify a name for the core thread pool
2 Core thread pool index is not effective
3. Remove the frame-level indicators and only keep the core monitoring indicators (the frame-level code type is completely deleted and will be considered later)

可观测性任务，优化线程池指标埋点功能
1需要为核心线程池指定名称
2核心线程池指标生效问题
3移除框架层指标只保留核心监控指标
* For compatibility purpose, use registry as the default config center when
     * there's no config center specified explicitly and
     * useAsConfigCenter of registryConfig is null or true
     */
    private void useRegistryAsConfigCenterIfNecessary() {
        
        if (environment.getDynamicConfiguration().isPresent()) {
            return;
        }
        if (CollectionUtils.isNotEmpty(configManager.getConfigCenters())) {
            return;
        }
        
        configManager.loadConfigsOfTypeFromProps(RegistryConfig.class);
        List<RegistryConfig> defaultRegistries = configManager.getDefaultRegistries();
        if (defaultRegistries.size() > 0) {
            defaultRegistries
                .stream()
                .filter(this::isUsedRegistryAsConfigCenter)
                .map(this::registryAsConfigCenter)
                .forEach(configCenter -> {
                    if (configManager.getConfigCenter(configCenter.getId()).isPresent()) {
                        return;
                    }
                    configManager.addConfigCenter(configCenter);
                    logger.info("use registry as config-center: " + configCenter);
                });
        }
    }
    private void initMetricsService() {