Support MinIO to be deployed on more than 32 nodes (#8492)

This PR implements locking from a global entity into
a more localized set level entity, allowing for locks
to be held only on the resources which are writing
to a collection of disks rather than a global level.

In this process this PR also removes the top-level
limit of 32 nodes to an unlimited number of nodes. This
is a precursor change before bring in bucket expansion.

cmd/lock-rest-client_test.go

@@ -19,17 +19,16 @@ package cmd
 import (
 	"testing"
 
-	"github.com/minio/dsync/v2"
-	xnet "github.com/minio/minio/pkg/net"
+	"github.com/minio/minio/pkg/dsync"
 )
 
 // Tests lock rpc client.
 func TestLockRESTlient(t *testing.T) {
-	host, err := xnet.ParseHost("localhost:9000")
+	endpoint, err := NewEndpoint("http://localhost:9000")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
 	}
-	lkClient := newlockRESTClient(host)
+	lkClient := newlockRESTClient(endpoint)
 	if lkClient.connected == 0 {
 		t.Fatalf("unexpected error. connection failed")
 	}
@@ -54,14 +53,4 @@ func TestLockRESTlient(t *testing.T) {
 	if err == nil {
 		t.Fatal("Expected for Unlock to fail")
 	}
-
-	_, err = lkClient.ForceUnlock(dsync.LockArgs{})
-	if err == nil {
-		t.Fatal("Expected for ForceUnlock to fail")
-	}
-
-	_, err = lkClient.Expired(dsync.LockArgs{})
-	if err == nil {
-		t.Fatal("Expected for Expired to fail")
-	}
 }