More flexible display of extra object in Field

[prensing]

Field2d can hold many objects. We use it to display visible AprilTags (ie live values of what is seen). We just added a display of where the robot thinks it is shooting.

This works well in Glass in the simulation. We can adjust the icons for different elements, including things like connecting them with a line.

I would like Elastic to have some of this ability, ie, the ability to customize the display of the different elements in a Field2d.

[amsam0]

Thought this might be useful: in our Elastic fork, we hardcoded custom colors for certain Field2d objects and also displayed certain objects as yellow circles (fuel). https://github.com/FRC-Team-955/2026-Dashboard-955/blob/53489596497c44d2e916bb21bb4dc64315aa8eaf/lib/widgets/nt_widgets/multi_topic/field_widget/field_widget.dart#L62-L87