[Workspace] Add a client in public side of workspace plugin

[SuZhou-Joe]

Is your feature request related to a problem? Please describe.

For the new introduced workspace plugin, we need a client in public side to help to communicate with server side of workspace.

Describe the solution you'd like

Add workspace client in public side of workspace plugin.

Describe alternatives you've considered

A clear and concise description of any alternative solutions or features you've considered.

Additional context

#4944