feat: introduce list_quorum="auto" to prefer quorum drives (#18084)

NOTE: This feature is not retro-active; it will not cater to previous transactions
on existing setups. 

To enable this feature, please set ` _MINIO_DRIVE_QUORUM=on` environment
variable as part of systemd service or k8s configmap. 

Once this has been enabled, you need to also set `list_quorum`. 

```
~ mc admin config set alias/ api list_quorum=auto` 
```

A new debugging tool is available to check for any missing counters.

internal/config/api/api.go

@@ -253,7 +253,7 @@ func LookupConfig(kvs config.KVS) (cfg Config, err error) {
 
 	listQuorum := env.Get(EnvAPIListQuorum, kvs.GetWithDefault(apiListQuorum, DefaultKVS))
 	switch listQuorum {
-	case "strict", "optimal", "reduced", "disk":
+	case "strict", "optimal", "reduced", "disk", "auto":
 	default:
 		return cfg, fmt.Errorf("invalid value %v for list_quorum: will default to 'strict'", listQuorum)
 	}

internal/config/api/help.go

@@ -58,7 +58,7 @@ var (
 		},
 		config.HelpKV{
 			Key:         apiListQuorum,
-			Description: `set the acceptable quorum expected for list operations e.g. "optimal", "reduced", "disk", "strict"` + defaultHelpPostfix(apiListQuorum),
+			Description: `set the acceptable quorum expected for list operations e.g. "optimal", "reduced", "disk", "strict", "auto"` + defaultHelpPostfix(apiListQuorum),
 			Optional:    true,
 			Type:        "string",
 		},