config conversion: Remove enable_{active,passive}_checks export.
config conversion: Fix object names in test config.
config conversion: Rename group attributes.

refs #4741
config conversion: Rename hostcheck to check.

refs #4741
config conversion: Move notification filters from service into notification.

refs #4741
config conversion: Move notification_interval|period from service to notification.

refs #4741
config conversion: Fix command exists checks by type.

refs #4741
config conversion: Rename dependencies.

refs #4741