FreeRTOS-LoRaWAN integration

[elsalahy]

Summary:

Umbrella issue for improving LoRaWAN FreeRTOS integration.

• [ ] Enable Tickless_IDLE mode and measure power consumption, see #84
• [x] Reduce logging overhead, see #90
• [x] Use MAC layer in delays DutyCycleWaitTime after update to v1.0, see #88
• [ ] Integrate RTC with LW FreeRTOS app, see #100