monitoring: state growth dashboard

Devnet - State Growth, from geth's own counters: live pebble size and the
ancient freezer, bytes per block, growth rate next to blocks per hour,
read latency p50/p95 by method class, pebble block-cache hit ratio,
account and storage reads, compaction time, disk I/O, days to full on
the VM disk, and a note on what this devnet cannot show.

Author: Task