Add vars parameter to notification templates, task icinga_serviceset swap

[gianmarco-mameli]

Hi,
The icinga_notification_template module doesn't have the possiblity to add vars to template, so I've implemented it and tested.

Also, while testing a complete recovery for my personal cluster, I've found that on the main task of the role, the icinga_serviceset is called after icinga_service, and that is a problem because every service connected to a serviceset, needs the service_set parameter, so I simply swapped the order, first service sets task and next the services task

Thanks