Recommend related packages on SUSE distributions

These packages are installed by default but they are not required so
there is no error if they are missing.

This should make the installation of Icinga2 more user friendly on SUSE
distributions.

refs #6920
Add "Provides: monitoring_daemeon" on SUSE distributions

to allow Icinga2 being a replacement for compatible monitoring daemons
like Icinga 1 or Nagios.

This should make the installation of Icinga2 more user friendly on SUSE
distributions.

refs #6920
Merge branch 'feature/recommend-suse-packages-6920'

fixes #6920