When the YamlObject::get() function override that returns a
std::optional got introduced, all tests were moved to it, leaving no
tests for the override that takes a default value. Reintroduce those
tests.
Reported-by: Florian Sylvestre <fsylvestre@baylibre.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>