feat: Single drive XL implementation (#14970)

Main motivation is move towards a common backend format
for all different types of modes in MinIO, allowing for
a simpler code and predictable behavior across all features.

This PR also brings features such as versioning, replication,
transitioning to single drive setups.

cmd/lock-rest-server.go

@@ -209,22 +209,7 @@ func (l *lockRESTServer) ForceUnlockHandler(w http.ResponseWriter, r *http.Reque
 // lockMaintenance loops over all locks and discards locks
 // that have not been refreshed for some time.
 func lockMaintenance(ctx context.Context) {
-	// Wait until the object API is ready
-	// no need to start the lock maintenance
-	// if ObjectAPI is not initialized.
-
-	var objAPI ObjectLayer
-
-	for {
-		objAPI = newObjectLayerFn()
-		if objAPI == nil {
-			time.Sleep(time.Second)
-			continue
-		}
-		break
-	}
-
-	if _, ok := objAPI.(*erasureServerPools); !ok {
+	if !globalIsDistErasure {
 		return
 	}