[#166] Fix getting s3 object with the FrostFS OID name

Prioritize getting s3 object with the key, which equals to valid FrostFS OID, rather than getting non-existent object with OID via native protocol for GET and HEAD requests

Signed-off-by: Nikita Zinkevich <n.zinkevich@yadro.com>

internal/data/tree.go

@@ -0,0 +1,27 @@
+package data
+
+import (
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+// NodeVersion represent node from tree service.
+type NodeVersion struct {
+	BaseNodeVersion
+}
+
+// BaseNodeVersion is minimal node info from tree service.
+// Basically used for "system" object.
+type BaseNodeVersion struct {
+	ID             uint64
+	OID            oid.ID
+	IsDeleteMarker bool
+}
+
+type NodeInfo struct {
+	Meta []NodeMeta
+}
+
+type NodeMeta interface {
+	GetKey() string
+	GetValue() []byte
+}