implement a safer completeMultipart implementation (#20227)

- optimize writing part.N.meta by writing both part.N
  and its meta in sequence without network component.

- remove part.N.meta, part.N which were partially success
  ful, in quorum loss situations during renamePart()

- allow for strict read quorum check arbitrated via ETag
  for the given part number, this makes it double safer
  upon final commit.

- return an appropriate error when read quorum is missing,
  instead of returning InvalidPart{}, which is non-retryable
  error. This kind of situation can happen when many
  nodes are going offline in rotation, an example of such
  a restart() behavior is statefulset updates in k8s.

fixes #20091

cmd/storage-rest-common.go

@@ -20,7 +20,7 @@ package cmd
 //go:generate msgp -file $GOFILE -unexported
 
 const (
-	storageRESTVersion       = "v62" // Introduce DeleteBulk internode API.
+	storageRESTVersion       = "v63" // Introduce RenamePart and ReadParts API
 	storageRESTVersionPrefix = SlashSeparator + storageRESTVersion
 	storageRESTPrefix        = minioReservedBucketPath + "/storage"
 )
@@ -44,6 +44,7 @@ const (
 	storageRESTMethodReadMultiple   = "/rmpl"
 	storageRESTMethodCleanAbandoned = "/cln"
 	storageRESTMethodDeleteBulk     = "/dblk"
+	storageRESTMethodReadParts      = "/rps"
 )
 
 const (