Make nightlies show rule timings

[Alex-Fischman]

When the egglog command line tool is run, we get timing information per rule (and per ruleset). It'd be nice to see that displayed somewhere on the nightlies, so we can get some idea of which rules are slow. Tasks:

• Parse the timing info (maybe PR egglog to make this easier)
• Run egglog on some large, representative benchmark (you might have to write this benchmark, or maybe you can Frankenstein all the small tests together)
• Display the timing info on the nightly

This issue is low priority, just a nice-to-have