feature: Math expressions

[Beanow]

In Grafana, typically the datasources themselves handle math in their respective query languages. Like PromQL or SQL.
Haven't looked around the Go landscape for any packages that might help, but this could add some neat new possibilities.

For example:

• CompletedLaps + NormalizedCarPosition = Lap progress as a float
• (BrakeBias - 0.5) * 2.0 = BrakeBias but ranging from -1 to +1
• max(BrakeTempFL, BrakeTempFR, BrakeTempRL, BrakeTempRR) = The temp of your hottest brake

Doing so with the current values would already be very useful.

Even crazier would be if time ranges could be supported. Something like:

• max(RPMs[3s]) = The highest RPM of the last 3 seconds. (Useful for "sustaining" the RPM value when you shifted)
• sum(ABS[0.5s]) = Meaningless number to visualize ABS as an increasing value rather than flickering between 0/1

Note that shows some design challenge in what max and friends are supposed to do or take as arguments.
The one with time ranges is more like PromQL. The current value one closer to Math.max() from JS.