Chart: losing the legend

### Current Behavior

After moving a chart to another page, the legend is no longer shown.

### Expected Behavior

When selecting "show legend" I would love to see the legend. When moving the chart to another page, the chart should look similar.

### Steps To Reproduce

- I have a chart node "Foo".
- I copy it to "Bar".
- Using the web browser edit dialogue I move the copy to different group in a different page. I notice that the legend is not shown anymore.
- I move "Bar" back to the original group and page and still, the legend is not shown.

### Environment

- Dashboard version: @flowfuse/node-red-dashboard 1.23.0
- Node-RED version: 3.1.9
- Node.js version: 18.20.4
- npm version: 10.7.0
- Platform/OS: Linux 6.8.12-5-pve #1 SMP PREEMPT_DYNAMIC PMX 6.8.12-5 (2024-12-03T10:26Z) x86_64 x86_64 x86_64 GNU/Linux on Proxmox VM host
- Browser: Firefox 136.0

### Have you provided an initial effort estimate for this issue?

I am not a FlowFuse team member