APis return Box<dyn Error> which isn't compatibile with useful ecosystem crates

[cpcloud]

A number of APIs, especially the new_pipeline().install() flavors return Box<dyn Error>. This trait bound is incompatible with useful ecosystem crates like anyhow, whose Context trait requires Box<dyn Error + Send + Sync + 'static>.

I'm happy to submit a PR to fix this. Are there any APIs where we don't want this trait bound?

[frigus02]

Good point. Using Box<dyn Error + Send + Sync + 'static> seems sensible to me. I can't think of a reason why we wouldn't want this. Can you, @jtescher?

[jtescher]

Yeah this sounds good. We want to unify the error types with the current MetricsError type in the future, but this can come first 👍