Add cache metrics

[MegaRedHand]

Having hit/miss metrics of Blocks might be useful

[Arkenan]

There's a single module (LRUCache) that implements cache for all schemas. We can add telemetry calls in that module for hits and misses, using the "table" as part of the metadata so we can filter in grafana. A PR to complete this issue should have:

• The :telemetry.execute calls
• The aggregation in Telemetry.Metrics
• The Grafana dashboards added