Explicit x-axis limits for scatter plot in ui-chart

### Description

Hi all,

I have been making x-y scatter plots of data that are best visualized with a fixed (i.e., not autoscaling) x-axis. The ui-chart node allows me to explicitly set the y-axis, but oddly, not the x-axis. There are tricks to do so (like creating a fake data set with x values at the limit, and null y-values - _thanks E1cid!_), and even trickier tricks for usage with multiple series, however, why make the user guess? This seems like very basic functionality, right after making time series plots. Any chance the **AWESOME** DB2 devs can add a xmin and xmax options to the scatter plot sub-options of ui-chart?

A huge thanks in advance!

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

I am no FlowFuse team member