Werk #12212: Make confirm dialog for downtimes more user friendly

Previously, there were misunderstandings about setting downtimes in service views. Without the option "Schedule downtimes on the affected hosts instead of on the individual services" the downtime was "only" set for the services of that view, not the host itself.

To make this clearer, the user can now choose between "Schedule downtime on host" and "Schedule downtime for services" in the confirm dialog for downtimes in such views. The above mentioned option for "...hosts instead of on the individual services" was removed.

To the list of all Werks