* feat: push metrics into catalog
* chore: minor cleanup
* fix: include db labels in chunk metric domains
* chore: fmt
* fix: don't allow dropping moving chunks
* chore: further tweaks
* chore: review feedback
* feat: use new_unregistered() for metric instruments instead of default
* chore: use &[KeyValue] instead of &Vec<KeyValue>
* refactor: make GauageValue non default constructible