Workspaces and virtual desktops

### Description of the new feature / enhancement

Currently, when launching a workspace in a new virtual desktop, it switches to the primary desktop and opens the windows there, even if the workspace name matches the virtual desktop name. It would be nice if workspaces could be saved with a named virtual desktop that it would use or create at launch.

### Scenario when this would be used?

When using virtual desktops to manage different work streams, and workspaces to start or resume that work stream.

### Supporting information

When I'm required to do task switching, separating tasks with virtual desktops helps me separate the context of each task, while retaining the progress of each.

Start by tracing the Workspaces launch flow and its handling of virtual desktops; the issue does not identify an entry point or test. Determine how a workspace should associate with a named desktop and what should happen when that desktop is absent, then validate launching and resuming workspaces across desktops.

Written by the indexing model from the issue text.