Add more peer information in `information_schema.cluster_info`

[WenyXu]

What type of enhancement is this?

User experience

What does the enhancement do?

Currently, the information_schema.cluster_info table provides limited details about cluster peers. To improve observability and debugging, we propose adding more peer-related information.

Enhancements:

• Metasrv
  • Indicate current leader.
• Datanode
  • Report workloads configuration
  • Provide resource information (e.g., memory, CPU if available).
  • Num of Leader/Follower regions
• Flownode
  • Provide resource information
  • Num of flow Job
• Frontend
  • Provide resource information

TODO

• Add cpus and memory_bytes fields to cluster_info table.
• Add status field to cluster table to display extension information of peer