dbus-manager: Add an out argument to CreateFolder
The CreateFolder DBus call accepts as argument the URI of the new folder to be created (e.g. 'file:///home/user/Desktop/New Folder'). If a folder with the same name already exists, CreateFolder will automatically append a sequential number to the path in order to create a new unique folder name (e.g. file:///home/user/Desktop/New Folder 2'). Add a 'CreateUri' DBus output argument to pass back to the caller the URI of the newly created folder.
Closes: #924 (closed)