[test] Wait the end of the wizard before continue

Can be usefull if computer is slow...

Change-Id: I54e755067795942ad8ddc6c7d8572d0a365e5d13
Signed-off-by: Laurent Redor <laurent.redor@obeo.fr>
[427803] Fix a wrong marker name.

MarkerType name has been changed in plugin.xml of
org.eclipse.sirius.diagram.ui but not in this class.

Change-Id: I3705352735f8bd601b68789a56c2ec2b5b33870b
Signed-off-by: Laurent Redor <laurent.redor@obeo.fr>