Fix review comments and new changes in config (#8515)

- Migrate and save only settings which are enabled
- Rename logger_http to logger_webhook and
  logger_http_audit to audit_webhook
- No more pretty printing comments, comment
  is a key=value pair now.
- Avoid quotes on values which do not have space in them
- `state="on"` is implicit for all SetConfigKV unless
  specified explicitly as `state="off"`
- Disabled IAM users should be disabled always

cmd/config/storageclass/storage-class.go

@@ -222,6 +222,9 @@ func LookupConfig(kvs config.KVS, drivesPerSet int) (cfg Config, err error) {
 
 	stateBool, err := config.ParseBool(env.Get(EnvStorageClass, kvs.Get(config.State)))
 	if err != nil {
+		if kvs.Empty() {
+			return cfg, nil
+		}
 		return cfg, err
 	}
 	ssc := env.Get(StandardEnv, kvs.Get(ClassStandard))