The flag IsContainer was not set, causing the QCborContainerPrivate to
become confused.
This commit also expands and subsumes the existing test for QCborValue
(non-Ref).
Change-Id: I5e52dc5b093c43a3b678fffd16b6a17c6f4a0676
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>