Chart - enable usage of left & right 'y' axis

### Description

Possibly related to https://github.com/orgs/FlowFuse/projects/15?pane=issue&itemId=32022297
But specifically to enable both left and right 'y' axis to be utilized independently, with different scaling.

This would be helpful for many user applications where 2 values are being compared on the same timescale, but have different y scaling, For example I'm monitoring a energy diverter and on the left y axis record the amount of power being diverted (Unit = Watts, scale = 0 - 4000), whilst on the right y axis record the operating temperature of the diverter (Unit = degC, scale = 0 - 50).
Currently using just the left y axis for both which results in the temperature being a flat line due to the power scale.
Same situation arises when comparing temperature & windspeed on a chart, as a visual comparison because users can then assess 'feelslike' temp.

Below is a random example

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

I am no FlowFuse team member