Support for remote tier management (#12090)

With this change, MinIO's ILM supports transitioning objects to a remote tier.
This change includes support for Azure Blob Storage, AWS S3 compatible object
storage incl. MinIO and Google Cloud Storage as remote tier storage backends.

Some new additions include:

 - Admin APIs remote tier configuration management

 - Simple journal to track remote objects to be 'collected'
   This is used by object API handlers which 'mutate' object versions by
   overwriting/replacing content (Put/CopyObject) or removing the version
   itself (e.g DeleteObjectVersion).

 - Rework of previous ILM transition to fit the new model
   In the new model, a storage class (a.k.a remote tier) is defined by the
   'remote' object storage type (one of s3, azure, GCS), bucket name and a
   prefix.

* Fixed bugs, review comments, and more unit-tests

- Leverage inline small object feature
- Migrate legacy objects to the latest object format before transitioning
- Fix restore to particular version if specified
- Extend SharedDataDirCount to handle transitioned and restored objects
- Restore-object should accept version-id for version-suspended bucket (#12091)
- Check if remote tier creds have sufficient permissions
- Bonus minor fixes to existing error messages

Co-authored-by: Poorna Krishnamoorthy <poorna@minio.io>
Co-authored-by: Krishna Srinivas <krishna@minio.io>
Signed-off-by: Harshavardhana <harsha@minio.io>

cmd/xl-storage-format-utils.go

@@ -103,11 +103,13 @@ func getFileInfo(xlMetaBuf []byte, volume, path, versionID string, data bool) (F
 	if err := json.Unmarshal(xlMetaBuf, xlMeta); err != nil {
 		return FileInfo{}, errFileCorrupt
 	}
+
 	fi, err := xlMeta.ToFileInfo(volume, path)
 	if err == errFileNotFound && versionID != "" {
 		return fi, errFileVersionNotFound
 	}
-	fi.XLV1 = true // indicates older version
+	fi.IsLatest = true // No versions so current version is latest.
+	fi.XLV1 = true     // indicates older version
 	return fi, err
 }