Redo how to handle stale dangling files (#7171)

foo.CORRUPTED should never be created because when
multiple sets are involved we would hash the file
to wrong a location, this PR removes the code.

But allows DeleteBucket() to work properly to delete
dangling buckets/objects. Also adds another option
to Healing where a user needs to specify `--remove`
such that all dangling objects will be deleted with
user confirmation.

cmd/xl-v1-healing_test.go

@@ -114,7 +114,7 @@ func TestHealObjectXL(t *testing.T) {
 		t.Fatalf("Failed to delete a file - %v", err)
 	}
 
-	_, err = obj.HealObject(context.Background(), bucket, object, false)
+	_, err = obj.HealObject(context.Background(), bucket, object, false, false)
 	if err != nil {
 		t.Fatalf("Failed to heal object - %v", err)
 	}
@@ -130,7 +130,7 @@ func TestHealObjectXL(t *testing.T) {
 	}
 
 	// Try healing now, expect to receive errDiskNotFound.
-	_, err = obj.HealObject(context.Background(), bucket, object, false)
+	_, err = obj.HealObject(context.Background(), bucket, object, false, false)
 	// since majority of xl.jsons are not available, object quorum can't be read properly and error will be errXLReadQuorum
 	if _, ok := err.(InsufficientReadQuorum); !ok {
 		t.Errorf("Expected %v but received %v", InsufficientReadQuorum{}, err)