Is your feature request related to a problem? Please describe (👍 if you like this request)

Add status APIs for shallow copy and IO pause/resume. The information will be exported to management components and users.

The responses might be like

• shallow copy status
  • status: pending/in-progress/completed/failed/unknown
  • progress: unit in percentage
• subsystem status
  • io: running/paused/stopped/...

Describe the solution you'd like

A clear and concise description of what you want to happen

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.

cc @DamiaSan @shuo-wu @LLParse @innobead