[SYS][BREAKING] Add gateway states, Offline mode and refactor sleep (#2020)

Gaterway states to improve LED management
Make the sleep function accessible outside BT
BREAKING remove sleep for ESP8266
BREAKING lowpowermode API changed to powermode and new mode definition

Co-authored-by: Florian <1technophile@users.noreply.github.com>

main/config_BT.h

@@ -32,7 +32,6 @@ extern void MQTTtoBT(char* topicOri, JsonObject& RFdata);
 extern void pubMainCore(JsonObject& data);
 extern void launchBTDiscovery(bool overrideDiscovery);
 extern void stopProcessing();
-extern void lowPowerESP32();
 extern String stateBTMeasures(bool);
 
 #ifdef ESP32