[Feature request] Bind desklets to workspace

In a single-monitor setup, it'd be great if desklets could be bound to a workspace, meaning: a desklet would only be visible on workspace 1, but not on workspace 2, 3, 4, etc.

Use-case: Say you're using

• the cryptocurrency desklet to show your cryptocurrency portfolio value or
• the notes desklet to display a to do-list on your desktop or
• any other desklet displaying potentially sensitive information

But now you're also

• video-conferencing and using screen sharing to work with colleagues or
• using a notebook to give a presentation to people

In both cases, chances are you'll reveal your desktop to a wider audience if you're not extremely careful (and accidents are likely to happen). Obviously, this creates privacy issues. There are two solutions as far as I can see:

1. You could create a separate user for "public" purposes and log back into your private account once you're done. This would, however, be impractical, as you'd constantly have to transfer data (presentations and such) between the two users.
2. If desklets were bound to one workspace, you could easily keep desklets on workspace 1 and simply switch to workspace 2 for the video conference / presentation part.

UI suggestion: one could integrate a toggle in the Settings section of the Desklets application where the user could turn desklet binding on or off. The default setting could even remain "Show desklets on all workspaces", just like it is now. This would keep everything 'as is' for users familiar with Cinnamon's behaviour so far, but would allow users with these specific needs to change Desklet behaviour accordingly.

The issue names no files, tests, or entry points. Start by locating Cinnamon's desklet settings and workspace visibility handling, then determine how a per-desklet workspace binding could fit the existing behavior. Done means desklets can be configured to show only on a selected workspace while preserving the current all-workspaces default.