Drag the Bar to Scroll

### Feature Description

Similar to niri's [Drag Window To Scoll Feature](https://github.com/niri-wm/niri/releases/tag/v25.11#Drag%20windows%20horizontally%20to%20scroll:~:text=Drag%20windows%20horizontally%20to%20scroll), being able to scroll the view horizontally with just the bar would be nice

### Use Case

This features allows the bar to effectively act as the titlebar in niri (with an extra plugin I made), and would make using niri without titlebars much more convenient.

### Compositor(s)

Niri

### If Other, please specify

_No response_

### Proposed Solution

_No response_

### Alternatives/Existing Solutions

_No response_