speed up startup sequence for all operations (#14148)

This speed-up is intended for faster startup times
for almost all MinIO operations. Changes here are

- Drives are not re-read for 'format.json' on a regular
  basis once read during init is remembered and refreshed
  at 5 second intervals.

- Do not do O_DIRECT tests on drives with existing 'format.json'
  only fresh setups need this check.

- Parallelize initializing erasureSets for multiple sets.

- Avoid re-reading format.json when migrating 'format.json'
  from really old V1->V2->V3

- Keep a copy of local drives for any given server in memory
  for a quick lookup.

cmd/globals.go

@@ -338,6 +338,9 @@ var (
 	globalServiceFreezeCnt int32
 	globalServiceFreezeMu  sync.Mutex // Updates.
 
+	// List of local drives to this node, this is only set during server startup.
+	globalLocalDrives []StorageAPI
+
 	// Add new variable global values here.
 )