Widget grouping

### Feature Description

It would be nice if you could put widgets into something like a folder, which when clicked on the bar would open a popup that displays the widgets inside.

### Use Case

My bar has a bunch of widgets like the color picker, notepad, clipboard or history which I like to keep there for easy access but sit unused most of the time and take up space.

### Compositor(s)

All compositors

### If Other, please specify

_No response_

### Proposed Solution

Here is a little mockup I made. There could even be the option to give the folder/group a title and change the icon to a set of icons from your icon library or a custom one.

### Alternatives/Existing Solutions

_No response_

Start with the feature description and attached mockup, then review how the desktop bar currently exposes widgets and opens popups. Clarify grouping behavior, folder titles, icon choices, and compositor expectations before implementation. Done means grouped widgets can be opened from the bar without permanently occupying separate space across all listed compositors.

Written by the indexing model from the issue text.