tests: Add copyright/licensing header to queue tests

This is put together through git archaeology:
```
git log glib/tests/queue.c
git log -- tests/queue-test.c
```

The following commits were too trivial to have meaningful copyright:
 - 8f02fac4ad
 - d81ac5339f
 - 29f2ced8eb
 - 1a2c5e155d
 - 8a90f5e9f6
 - 45dae4b506
 - 2aa71ab63b
 - 3a74ad128e

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Helps: #1415

glib/tests/queue.c

@@ -1,3 +1,24 @@
+/*
+ * Copyright 1999 Jeff Garzik
+ * Copyright 1999 Tim Janik
+ * Copyright 2004 Soeren Sandmann
+ * Copyright 2006 Martyn James Russell
+ * Copyright 2004, 2005, 2010, 2019 Red Hat, Inc.
+ * Copyright 2011 Samsung
+ * Copyright 2018 Tapasweni Pathak
+ * Copyright 2019 Endless Mobile, Inc.
+ * Copyright 2020 Emmanuel Fleury
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * See the included COPYING file for more information.
+ */
+
 #undef G_DISABLE_ASSERT
 #undef G_LOG_DOMAIN