Create queue and pass discovered nodes to it

[ABotelho23]

We need to learn how to implement queues.

See, https://github.com/ABotelho23/aacdnProject/blob/hubCode-flask/hubAiocoap.py

At DiscoveryThread, need to pass a queue created in main(), and also when creating FlaskThread.

DiscoveryThread does queueName.put(...) of CoapNode object for every discovered node and FlaskThread does queueName.get(...). FlaskThread then displays a box with the information from the CoapNode objects from the queue.

[ABotelho23]

Putting this on backburner to polish the rest of project