Meta-data passed to add_item().
You should use RecentManager::Data if you want to control the meta-data associated to an entry of the recently used files list when you are adding a new file to it.
- display_name: the string to be used when displaying the file inside a RecentChooser
- description: a user readable description of the file
- mime_type: the mime type of the file
- app_name: the name of the application that is registering the file
- app_exec: the command line that should be used when launching the file
- groups: the list of group names to which the file belongs to
- is_private: whether the file should be displayed only by the applications that have registered it
