RuntimeCatalogue: offline usage

[pchainho]

To enable offline usage, use current stored version of catalogue objects in case runtimeFactory.isOnline(). retrieves false.

• Add runtimeCatalogue URL as data storage key in order to query it without the cguid

• before calling the catalogue backend check runtimeFactory.isOnline(). Otherwise, check that isSavedDescriptor = false and use it, if not call runtimeFactory.listenOnline(getDescriptor) where getDescriptor has the logic to retrieve the descriptor from backend.