[Workspace] Validate the workspace id in the url

[SuZhou-Joe]

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

For now, workspace plugin will take whatever in url path if the path matches the pattern of workspace, there should be a validation to check if the workspace in url is valid.

Describe the solution you'd like

Check when workspace start to setup and gives an friendly error page when user can not get access to the specific workspace.

Describe alternatives you've considered

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

Additional context

#4944