Add Shift+Left Click for Canvas Navigation

### Feature Idea

## Current Behavior
- Middle mouse button press and drag: Moves the canvas
- Left click and drag on empty space: Moves the canvas
- Left click and drag on nodes: Moves the nodes

## Requested Feature
Add the ability to pan/move the canvas using Shift+Left Click drag, regardless of whether clicking on nodes or empty space.

## Why is this needed?
Middle mouse button usage for extended periods can cause hand fatigue

Would it be possible to implement this alternative canvas navigation method?

### Existing Solutions

_No response_

### Other

_No response_