Send lora radio to sleep on sensor node with deep sleep enabled?

[ThePradox]

Hi and thanks for the great project.

I may be missing something but is there a reason for not calling radio.sleep() in fdrs_node.h?

I tested it on my simple sensor node with an sx1262 and found no problems so far. I lack the equipment to measure if it makes a huge difference in power consumption, but most radio vendors advertise very low sleep currents.