[DRAFT] Add additional statistics and histogram visualization

[naddeoa]

This adds a few statistics so the report, as well as a visualization of the global histogram, which I find very useful with another tool hey.

I improvised the color scheme to match the existing one (yellow/purple).

I kept it out of the individual smaller reports for fear of making the output too verbose.

[naddeoa]

Added the DRAFT prefix to get some feedback on the unwrapping. I don't write rust enough to know exactly what's safe/best practices there.