Uniformise the way default profiles are handled
Whether sources are added, folders are created or sources (and folders) are imported, we may have to handle default profile value.
However, sometimes it uses the default value configured in the XmlTabConfig, sometimes it uses Constants.DEFAULT_PROFILE, sometimes it uses 1, sometimes it uses 0.
If the XmlTabConfig is the holder of the default value for all the services (and it can!), then it should be provided in the constructor of all the services and be reused.