Allow launching of new instances of apps from dock by middle click

### Feature Description

Add an option to allow launching of new instances of apps from the dock by middle clicking.

### Use Case

Some apps as terminal, web browsers, file browsers, are commonly multi instance. It would be a very nice to have for someone with a mouse oriented workflow.

### Compositor(s)

All compositors

### If Other, please specify

_No response_

### Proposed Solution

_No response_

### Alternatives/Existing Solutions

_No response_