ADHOC: add read needle meta grpc (#3581)

* ADHOC: add read needle meta grpc

* add test

* nit

Co-authored-by: root <root@HQ-10MSTD3EY.roblox.local>

weed/storage/volume_read.go

@@ -80,6 +80,24 @@ func (v *Volume) readNeedle(n *needle.Needle, readOption *ReadOption, onReadSize
 	return -1, ErrorNotFound
 }
 
+// read needle at a specific offset
+func (v *Volume) readNeedleMetaAt(n *needle.Needle, offset int64, size int32) (err error) {
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
+	// read deleted meta data
+	if size < 0 {
+		size = -size
+	}
+	err = n.ReadNeedleMeta(v.DataBackend, offset, Size(size), v.Version())
+	if err == needle.ErrorSizeMismatch && OffsetSize == 4 {
+		err = n.ReadNeedleMeta(v.DataBackend, offset+int64(MaxPossibleVolumeSize), Size(size), v.Version())
+	}
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 // read fills in Needle content by looking up n.Id from NeedleMapper
 func (v *Volume) readNeedleDataInto(n *needle.Needle, readOption *ReadOption, writer io.Writer, offset int64, size int64) (err error) {
 	v.dataFileAccessLock.RLock()