CXXCBC-582: Add cluster labels, keyspace & outcome in metrics

[DemetrisChr]

Motivation

The Extended Observability RFC revisions 24 & 25 require us to record additional metrics tags: bucket, scope, collection, outcome, and cluster labels (name & UUID)

Changes

• Update config parsing to include clusterName & clusterUUID
• Create a new core::metrics::meter_wrapper class that watches for config updates and keeps track of cluster labels
• Replace all meter references in the core with the meter wrapper
• The meter wrapper is responsible for encoding the metric attributes & inserts tags for the cluster labels, if those are supported by the cluster
• Add some tests for KV

Results

Tests pass

Known issues

Non-KV operation metrics don't currently report collection, bucket and scope names.