Increase font size in displays of traces in fun-stepper

[kfisler]

The font is barely readable (for example, I couldn't recognize that the blip on my screen between call and value was an arrow until I looked very closely). Would also help to have the text be horizontal rather than slanted.

[prestontw]

Having the text slanted was my way of not having the text clump together. Having all of the text horizontal is an illegible mess.