UN does not export an updated list of resources

[frisso]

Currently the UN reads the local file that tells which resources are available.
However, if those resources change (e.g., a VLAN is used in an endpoint), their description is not updated and re-sent to the message broker.
This creates troubles for the upper layer orchestrator, as it cannot know which resources have already been consumed, hence some decisions may be wrong.

[ivanocerrato]

As a first step, this issue requires to define a hierarchy of classes that represent the content of the JSON (this is similar to what we already do with the NF-FG).
Then, at the boot of the un-orchestrator the objects are filled with the proper information (currently they are read from a file). These information ca then be dynamically changed at runtime; each time that the content of an object changes, the json must be exported on the double decker network.