Refactor logging

You'll probably want me to break this out into smaller pieces, but since I did the work I thought I'd put it in front of folk and see what they think. I essentially copied the logging in sidekiq. I set about removing the logging all together in favor of instrumentation, but it didn't seem like they're really a one-to-one correlation. Right now, there's only one log subscription -- for the `handle_request` method.

I can reduce this to a pull request that just adds the instrumentation for `handle_request` and its corresponding subscriber, which would probably be better...

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@localshred