考虑增加指标埋点dashboard

[songxiaosheng]

• [ ] I have searched the issues of this repository and believe that this is not a duplicate.
• [ ] I have checked the REAMDE of this repository and believe that this is not a duplicate.

Is your feature request related to a problem? Please describe.

A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] 目前监控指标可以通过普罗米修斯显示dubbo内部并没有存储或者显示这些指标项的方式，

Describe the solution you'd like

A clear and concise description of what you want to happen. 考虑增加一个导航链接到grafana或者内部嵌套iframe的形式，又或者dubbo admin主动查询存储指标的系统例如普罗米修斯来自行展示指标数据

Describe alternatives you've considered

A clear and concise description of any alternative solutions or features you've considered.

Additional context

Add any other context or screenshots about the feature request here.