[issues/#45+#49] Enhance error feedback in semtech adapter
[issues/#45+#49] Enhance error feedback in semtech adapter

mgranberry/ttn,LoRaWanSoFa/ttn,jvanmalder/ttn,mgranberry/ttn,mgranberry/ttn,TheThingsNetwork/ttn,TheThingsNetwork/ttn,LoRaWanSoFa/ttn,TheThingsNetwork/ttn,jvanmalder/ttn,jvanmalder/ttn