Compiler: Add "Top 10 slowest modules" to --stats output

[nobodywasishere]

Rebase of #12942 on current release

[straight-shoota]

I'm wondering if we could polish the output a bit.
One issue is that the modules listed in "Top 10 slowest modules" overlap with those of "These modules were not reused". That creates a lot of noise.
Perhaps we could instead sort the list in "These modules were not reused" by compilation time (and print the time)?
I'm not sure if preserving the current ordering has any inherent value.
Or maybe we would only want to show the top 10 slowest modules when no previous files were reused (i.e. in the reused.zero? branch)? In that case we could still print the compilation time alongside the not-reused modules when 0 < reused < units.size.

The compilation time of individual modules should be in the order of seconds (or less than that) on reasonably modern hardware.
So formatting the durations with hours and minutes seems unergonomic. I think it would be reasonable to use a smaller unit there. seconds seems like a good fit. Or maybe even autoscale to form a nice human-readable presentation? A prototype for that would be Benchmark::Ips#human_iteration_time.