Add Switchbot support and discovery. (#995)

* Use a task to process immediate BLE actions to prevent MQTT disconnection if the action takes too long to complete.

* Add state_on and state_off parameters to createDiscovery

main/config_mqttDiscovery.h

@@ -88,7 +88,7 @@ extern void createDiscovery(const char* sensor_type,
                             int off_delay,
                             const char* payload_available, const char* payload_not_avalaible, bool gateway_entity, const char* command_topic,
                             const char* device_name, const char* device_manufacturer, const char* device_model, const char* device_mac, bool retainCmd,
-                            const char* state_class);
+                            const char* state_class, const char* state_off = nullptr, const char* state_on = nullptr);
 
 /**
  * @brief Create a message for Discovery Device Trigger. For HA @see https://www.home-assistant.io/integrations/device_trigger.mqtt/