[Workspace] Allow copy/duplicate saved objects among workspaces

[gaobinlong]

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

With workspace feature enabled, in the saved object management page or the visualization page, we should allow users to copy or duplicate the saved objects in one workspace to another, the copied saved objects are new saved objects in the target workspace, not reference.

Here are some mockups about this functionality:

Describe the solution you'd like

1. Firstly, we need to implement a new copy/duplicate API which can be called by the UI.
2. Secondly, add all the UI change of this functionality.