[Workspace] Restrict access to data sources for non dashboard admin

[wanglam]

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

This is a feature request. After the workspace enabled, the data sources can only be configured by the dashboard admin. The data sources can be specified by the dashboard admin when creating the workspace, and other users can only see the allocated data sources in the workspaces for which they have permissions.

Describe the solution you'd like

We are going to add some specific for data source saved objects in the workspace client wrapper. For saved object client find method, we will overwrite the workspace options to the user permitted workspaces id if no workspaces options provided. For other methods in saved object client, we will always return false in the data source saved object permission validation method if no workspaces in data source saved object property.

Describe alternatives you've considered

N/A

Additional context

#4944