speed up operate-source show

[GMHDBJD]

Is your feature request related to a problem? Please describe

operate-source show tasks a long time.

Describe the feature you'd like

operate-source show quickly return like list-member

Describe alternatives you've considered

consider combine operate-source show to list-member --source

Teachability, Documentation, Adoption, Migration Strategy

Maybe we can simply return source relations and no need to get response from worker.

[lance6716]

sources[1].msg will be filled with running status, so that's different with list-member --source