lorawan cleanup and optimizations:

- Remove all default loraconf default initialisation in lorawan examples (Region Settings takes care of this now)
- Remove retries while receiving JoinAccept and increase LoraRX to 10s (no need to wait more than 10s)
- Add constants for RegionSetting default frequencies
- Standardize all lora default configurations in lora examples
- Add new AT+LW=NET,(ON|OFF) command in atcmd example

examples/lora/lorawan/basic-demo/keys-default.go

@@ -2,10 +2,16 @@
 
 package main
 
+import (
+	"tinygo.org/x/drivers/lora/lorawan"
+)
+
 // These are sample keys, so the example builds
 // Either change here, or create a new go file and use customkeys build tag
 func setLorawanKeys() {
 	otaa.SetAppEUI([]uint8{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00})
 	otaa.SetDevEUI([]uint8{0xB3, 0xD5, 0x41, 0x00, 0x0A, 0xF1, 0xA4, 0x45})
 	otaa.SetAppKey([]uint8{0x12, 0x22, 0xA3, 0xFF, 0x0C, 0x7B, 0x76, 0x7B, 0x8F, 0xD3, 0x12, 0x4F, 0xCE, 0x7A, 0x32, 0x16})
+	lorawan.SetPublicNetwork(true)
+
 }