Add ObjectTagging Support (#8754)

This PR adds support for AWS S3 ObjectTagging API as explained here
https://docs.aws.amazon.com/AmazonS3/latest/dev/object-tagging.html

cmd/fs-v1-metadata.go

@@ -182,9 +182,14 @@ func (m fsMetaV1) ToObjectInfo(bucket, object string, fi os.FileInfo) ObjectInfo
 			objInfo.Expires = t.UTC()
 		}
 	}
+
+	// Add user tags to the object info
+	objInfo.UserTags = m.Meta[xhttp.AmzObjectTagging]
+
 	// etag/md5Sum has already been extracted. We need to
 	// remove to avoid it from appearing as part of
 	// response headers. e.g, X-Minio-* or X-Amz-*.
+	// Tags have also been extracted, we remove that as well.
 	objInfo.UserDefined = cleanMetadata(m.Meta)
 
 	// All the parts per object.