A new command line tool to easily set the start and estimated end time
of a journey on the mock service.
May be used on the SDK for testing

Signed-off-by: Guillaume Desmottes <guillaume.desmottes@collabora.co.uk>
Reviewed-by: Justin Kim <justin.kim@collabora.com>
Differential Revision: https://phabricator.apertis.org/D5378