use `tracing`'s structured logging

[aatifsyed]

Before: https://github.com/ChainSafe/forest/blob/9e3ed095a32d14a293ce7ed7b52b48d74d3b67b3/src/chain/store/chain_store.rs#L221 After:

info!(epoch = %ts.epoch(), key = %ts.key(), "new heaviest tipset");

Before: https://github.com/ChainSafe/forest/blob/9e3ed095a32d14a293ce7ed7b52b48d74d3b67b3/src/rpc/channel.rs#L360 After:

tracing::error!(?e, "Failed to serialize channel message");

Plan

• refactor all tracing callsites
  • Could this be automated with synsert?
• educate team on
  • std::error::Error and anyhow::Error's design
  • (structured) logging principles
    • Each info string or above should be unique and descriptive
    • Fields should be structured so that we can run metrics on them
    • Logging vs end-user messages
• [hard] write CI

Motivation

Either... or all error messages should use the ?e or a variant of that. If we do the latter, it should be enforced in CI.

Originally posted by @LesnyRumcajs in https://github.com/ChainSafe/forest/issues/4128#issuecomment-2036753097