[#212] Support CORS container for CORS settings

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

internal/handler/frostfs_mock.go

@@ -52,6 +52,10 @@ func (t *TestFrostFS) SetContainer(cnrID cid.ID, cnr *container.Container) {
 	t.containers[cnrID.EncodeToString()] = cnr
 }
 
+func (t *TestFrostFS) SetObject(addr oid.Address, obj *object.Object) {
+	t.objects[addr.EncodeToString()] = obj
+}
+
 // AllowUserOperation grants access to object operations.
 // Empty userID and objID means any user and object respectively.
 func (t *TestFrostFS) AllowUserOperation(cnrID cid.ID, userID user.ID, op acl.Op, objID oid.ID) {