When this application is launched, it tries to download
the first image from the git repository hosting the source
of this application.
Once the download is completed, the image is displayed and
a 500ms timer is started to download the other image,
cycling through them until the application is terminated.

Apertis: https://phabricator.apertis.org/T3836



Reviewed-by: Emanuele Aina <emanuele.aina@collabora.co.uk>
Signed-off-by: Justin Kim <justin.kim@collabora.com>
Differential Revision: https://phabricator.apertis.org/D6857