Tracing

[9ary]

Following a suggestion by @bb010g, this would be a cleaner way to implement progress reporting.

my preference: i'd not pass around progress bars, but rather use opentelemetry/minitrace/tracing to instrument your whole crate, and then report progress on the CLI based on emissions from that local telemetry.

https://lib.rs/crates/tracing-indicatif exists if you want to look at some code for that option.

The current hooks are fine, but the need to pass objects around pollutes the entire code base, so it'd be neat to get rid of them.