Add virtual screen global settings

Samson Ngalande

It would be nice to have global settings for each virtual screen that you create so that you don't change settings for each service item you add/re-use (e.g. song/announcement/ content). There can be an option to override the global setting if you want the item to have a different look than the other items in the same category. otherwise, it's tedious to always change the settings for each item you add/re-use