Running apps per display

### Feature Description

Would be great to be able to see all running apps per monitor/display (all workspaces for given monitor/output/dsiplay)

### Use Case

I use Niri and flipping through all workspaces (with checkbox "Running Apps Only in Current Workspace" selected), or having all apps from all monitors displayed is not ideal.

### Compositor(s)

- [ ] All compositors
- [x] Niri
- [ ] Hyprland
- [ ] MangoWC (dwl)
- [ ] Sway
- [ ] Other (specify below)

### Proposed Solution

Add checkbox in the setup limiting running apps per display/output/monitor (preferred), or maybe in case of multiple bars, limiting to the display(s) the bar is assigned to.

### Alternatives/Existing Solutions

I think noctalia has this option

Start by tracing the setup option for “Running Apps Only in Current Workspace” and the running-apps display for the Niri compositor. Determine how monitor/output assignment and multiple bars are represented, then define the checkbox behavior for showing apps from all workspaces on one display; done means the selected display shows only its apps without breaking existing workspace filtering.

Written by the indexing model from the issue text.