feat: make the group frame more easy to resize

### What problem are you experiencing?

When organizing workflows, I usually need to zoom out to move things, and for a group I often have to zoom in really close, then click the tiny 3px corner, then zoom out to drag the frame, sometimes I have to repeat again. I do this nearly every time, it makes using the app/comfyUI more difficult.

Few suggestions: make the corner sizer larger, or make it's customizable, or make the corner like a fixed size that scales with the viewport/zoom (see screenshot).

It would also be great if I could drag from any corner, and not just the bottom right. In a perfect world the nodes and groups would work like in Blender.

### When does this problem occur?

- When working on any medium size workflow, which is 95% of any workflow that is doing something useful.

### How often do you encounter this problem?

Multiple times per day

### How much does this problem affect your workflow?

Causes moderate inconvenience

### Current workarounds

_No response_

### Ideas for solutions (Optional)

_No response_

### Additional context

_No response_