return errors if dataDir is missing during HeadObject() (#18477)

Bonus: allow replication to attempt Deletes/Puts when
the remote returns quorum errors of some kind, this is
to ensure that MinIO can rewrite the namespace with the
latest version that exists on the source.

cmd/xl-storage-format-v2.go

@@ -1186,6 +1186,8 @@ func (x *xlMetaV2) AppendTo(dst []byte) ([]byte, error) {
 	return append(dst, x.data...), nil
 }
 
+const emptyUUID = "00000000-0000-0000-0000-000000000000"
+
 func (x *xlMetaV2) findVersionStr(key string) (idx int, ver *xlMetaV2Version, err error) {
 	if key == nullVersionID {
 		key = ""