[#214] object: Implement Get\Head requests for EC object

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

object/ecinfo.go

@@ -0,0 +1,69 @@
+package object
+
+import (
+	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/refs"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+type ECChunk object.ECChunk
+
+func (c *ECChunk) SetID(id oid.ID) {
+	objV2 := new(refs.ObjectID)
+	id.WriteToV2(objV2)
+	c.ID = *objV2
+}
+
+// ToV2 converts ECChunk to v2 ECChunk message.
+//
+// Nil ECChunk converts to nil.
+func (c *ECChunk) ToV2() *object.ECChunk {
+	return (*object.ECChunk)(c)
+}
+
+func NewECChunkFromV2(v2 *object.ECChunk) *ECChunk {
+	return (*ECChunk)(v2)
+}
+
+type ECInfo object.ECInfo
+
+// NewECInfoFromV2 wraps v2 ECInfo message to ECInfo.
+//
+// Nil object.ECInfo converts to nil.
+func NewECInfoFromV2(v2 *object.ECInfo) *ECInfo {
+	return (*ECInfo)(v2)
+}
+
+// NewECInfo creates and initializes blank ECInfo.
+func NewECInfo() *ECInfo {
+	return NewECInfoFromV2(new(object.ECInfo))
+}
+
+// ToV2 converts ECInfo to v2 ECInfo message.
+//
+// Nil ECInfo converts to nil.
+func (s *ECInfo) ToV2() *object.ECInfo {
+	return (*object.ECInfo)(s)
+}
+
+func (s *ECInfo) Marshal() ([]byte, error) {
+	return (*object.ECInfo)(s).StableMarshal(nil), nil
+}
+
+func (s *ECInfo) Unmarshal(data []byte) error {
+	return (*object.ECInfo)(s).Unmarshal(data)
+}
+
+// MarshalJSON implements json.Marshaler.
+func (s *ECInfo) MarshalJSON() ([]byte, error) {
+	return (*object.ECInfo)(s).MarshalJSON()
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (s *ECInfo) UnmarshalJSON(data []byte) error {
+	return (*object.ECInfo)(s).UnmarshalJSON(data)
+}
+
+func (s *ECInfo) AddChunk(chunk ECChunk) {
+	s.Chunks = append(s.Chunks, *chunk.ToV2())
+}