MR Analytics: Add yAxis formatter

What does this MR do and why?

This MR adds a formatter method for the yAxis to the throughput chart on MR Analytics. This ensures that we use decimal numbers for axis labels like 0.5 instead of displaying 500m.

Screenshots or screen recordings

see also !70373 (merged))

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #246790 (closed)