Parallel ledger loader & I/O performance improvements:

- Only duplicate records from archive to writable during online_delete.
- Log duration of nodestore reads.
- Include nodestore counters in perf_log output.
- Remove gratuitous nodestore activity counting.
- Report initial sync duration in server_info and perfLog.
- Report state_accounting in perfLog.
- Make state_accounting durations more accurate.
- Parallel ledger loader.
- Config parameter to load ledgers on start.

src/ripple/core/impl/Config.cpp

@@ -426,6 +426,9 @@ Config::setup(
     std::string ledgerTxDbType;
     Section ledgerTxTablesSection = section("ledger_tx_tables");
     get_if_exists(ledgerTxTablesSection, "use_tx_tables", USE_TX_TABLES);
+
+    Section& nodeDbSection{section(ConfigSection::nodeDatabase())};
+    get_if_exists(nodeDbSection, "fast_load", FAST_LOAD);
 }
 
 void