Add shell operation ability to polaris

[chuntaojun]

What is the feature you want to add?

Allows users to interact with polaris through shell commands, for example

1. View service or service instance
2. View service governance rules information
3. Do some operation and maintenance capabilities for polaris, such as forcing update of internal cache, restarting apisever, etc.

Why do you want to add this feature?

Provide command line interaction capabilities for Polaris, and provide another way of operation and maintenance capabilities and experience

How to implement this feature?

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

[li-xiao-shuang]

我可以尝试搞下这个任务，第一版可以先实现一些查询命令 不知道polaris是否有一些openapi?

[chuntaojun]

see https://github.com/polaris-contrib/polarisctl