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/background-newdisks-heal-ops.go

@@ -289,20 +289,20 @@ func initAutoHeal(ctx context.Context, objAPI ObjectLayer) {
 }
 
 func getLocalDisksToHeal() (disksToHeal Endpoints) {
-	for _, ep := range globalEndpoints {
-		for _, endpoint := range ep.Endpoints {
-			if !endpoint.IsLocal {
-				continue
-			}
-			// Try to connect to the current endpoint
-			// and reformat if the current disk is not formatted
-			disk, _, err := connectEndpoint(endpoint)
-			if errors.Is(err, errUnformattedDisk) {
-				disksToHeal = append(disksToHeal, endpoint)
-			} else if err == nil && disk != nil && disk.Healing() != nil {
-				disksToHeal = append(disksToHeal, disk.Endpoint())
-			}
+	for _, disk := range globalLocalDrives {
+		_, err := disk.GetDiskID()
+		if errors.Is(err, errUnformattedDisk) {
+			disksToHeal = append(disksToHeal, disk.Endpoint())
+			continue
 		}
+		if disk.Healing() != nil {
+			disksToHeal = append(disksToHeal, disk.Endpoint())
+		}
+	}
+	if len(disksToHeal) == globalEndpoints.NEndpoints() {
+		// When all disks == all command line endpoints
+		// this is a fresh setup, no need to trigger healing.
+		return Endpoints{}
 	}
 	return disksToHeal
 }