Tenets:
1. Limit thread names to 15 characters
2. Prefix all Solana-controlled threads with "sol"
3. Use Camel case. It's more character dense than Snake or Kebab case
#### Summary of Changes
This PR enables RocksDB read side performance metrics to report to blockstore_rocksdb_read_perf.
The sampling rate is controlled by an env arg `SOLANA_METRICS_ROCKSDB_PERF_SAMPLES_IN_1K`,
specifies the number of perf samples for every 1000 operations. The default value is set to 10, meaning
we will report 10 out of 1000 (or 1/100) reads.
The metrics are based on the RocksDB [PerfContext](https://github.com/facebook/rocksdb/blob/main/include/rocksdb/perf_context.h).
It includes many useful metrics including block read time, cache hit rate, and time spent on decompressing the block.
This PR enables blockstore to periodically report RocksDB column family properties.
The reported properties are under blockstore_rocksdb_cfs, and the properties also
support group by operation on cf_name.
Michael Vines
Yueh-Hsuan Chiang