<!-- Please make sure that your PR is aligned with the guidelines in
CONTRIBUTING.md to the best of your ability. -->
<!-- Good PRs have tests! Make sure you have sufficient test coverage.
-->
## Description
<!-- Describe the changes you've made. You may include any justification
you want here. -->
I've used the popular `owo-colors` library to colourise the output of
the `packet_inspector`.
This makes it a lot easier to see who's sending what for debugging
purposes.
In future, I'd like to be able to filter out common, low-information
packets like `SetPlayerPosition` and `KeepAlive` as well, but that's not
in this PR.

## Test Plan
No tests - just eyeball 😄.
Adds `tracing` to `valence_protocol` so we can log debug info about
partially decoded packets. `packet_inspector` has been set to print log
messages at the debug level.