feat(goleveldb): add Prometheus metrics

[melekes]

To use in CometBFT, replace cometbft-db with "github.com/cometbft/cometbft-db v0.8.1-0.20231130153829-e15cd32378cf" in your go.mod file.

Example list of metrics for blockstore db:

cometbft_db_blockstore_BlockCacheSize - goleveldb block cache size
cometbft_db_blockstore_IORead - N of bytes read
cometbft_db_blockstore_IOWrite - N of bytes written
cometbft_db_blockstore_TotalLevelDurations - Compaction duration
cometbft_db_blockstore_TotalLevelRead - N of MB read
cometbft_db_blockstore_TotalLevelSizes - N of MB compacted
cometbft_db_blockstore_TotalLevelTablesCounts - N of tables compacted
cometbft_db_blockstore_TotalLevelWrite - N of MB written
cometbft_db_blockstore_OpenedTablesCount - N of open goleveldb tables
cometbft_db_blockstore_batch_duration_ms - Batch#Write(false) duration in ms
cometbft_db_blockstore_batch_sync_duration_ms - Batch#Write(true) duration in ms
cometbft_db_blockstore_delete_duration_ms - Delete() duration in ms
cometbft_db_blockstore_delete_sync_duration_ms - DeleteSync() duration in ms
cometbft_db_blockstore_get_duration_ms - Get() duration in ms
cometbft_db_blockstore_set_duration_ms - Set() duration in ms
cometbft_db_blockstore_set_sync_duration_ms - SetSync() duration in ms

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.