[#311] Change object owner for anonymous put

Signed-off-by: Marina Biryukova <m.biryukova@yadro.com>

internal/frostfs/frostfs.go

@@ -237,6 +237,12 @@ func (x *FrostFS) CreateObject(ctx context.Context, prm layer.PrmObjectCreate) (
 	obj.SetAttributes(attrs...)
 	obj.SetPayloadSize(prm.PayloadSize)
 
+	if prm.BearerToken == nil && prm.PrivateKey != nil {
+		var owner user.ID
+		user.IDFromKey(&owner, prm.PrivateKey.PublicKey)
+		obj.SetOwnerID(&owner)
+	}
+
 	if len(prm.Locks) > 0 {
 		lock := new(object.Lock)
 		lock.WriteMembers(prm.Locks)