Delete unnecessary menu.ini's and update puppet manifests

refs #6639
Add configuration.php to Doc Module

refs #6639
Add Menu configuration in Monitoring Module

refs #6639
Change Menu load from config ini files to self provided configuration

refs #6639
Implement Module self provided configuration for menus

refs #6639
Remove menu.ini from icingaweb2.spec

refs #6639
Merge branch 'master' into bugfix/modules-menu-provider-6639
Merge branch 'bugfix/modules-menu-provider-6639'

refs #6639