[Client/Service Discovery] RM service discovery in client (70e5fb6f)

## Summary
Cherry-pick `70e5fb6f1e0ae050143626963164f88d58422d6a` into the `master` merge flow.

## Commit
- source commit: `70e5fb6f1e0ae050143626963164f88d58422d6a`
- source repo: `bufferflies/pd`

## Target
- branch: `master`

## Validation
- run focused client/service-discovery validation after cherry-pick integration

ref #10516