[RF] Improve Home Assistant auto discoverability (#2057)

* add '-DvalueAsATopic=true' to RF based environments
add '-DvalueAsATopic=true' to RF based environments. Required to support changes in zgatewayRF.ino for Home Assistant discoverability

* Modify gatewayRF to improve Home Assistant auto discoverability
Pass "recieved" as the type argument and switchRF[0] as the subtype argument to announceDeviceTrigger() which will cause recieved codes to be picked up by home assistant as triggers, i.e. When setting up automations in Home Assistant, selecting a `device` trigger and an OMG device will allow the user to select a code picked up during the autoDiscover window as the trigger for the automation, for example "1394004" recieved. In order to support this, the `'-DvalueAsATopic=true'` argument must be added to all environments using the RF Library

Also change getUniqueId() call to remove leading '-' which will prevent MQTT topics having '--' in them

---------

Co-authored-by: James Carey <james.carey@uws.ac.uk>

environments.ini

@@ -277,6 +277,7 @@ build_flags =
   ${com-esp32.build_flags}
   '-DZgatewayRF="RF"'
   '-DGateway_Name="OMG_ESP32_RF"'
+  '-DvalueAsATopic=true'
 custom_description = RF gateway using RCSwitch library
 
 [env:esp32dev-pilight]
@@ -1436,6 +1437,7 @@ build_flags =
   ${com-esp.build_flags}
   '-DZgatewayRF="RF"'
   '-DGateway_Name="OMG_ESP8266_RF"'
+  '-DvalueAsATopic=true'
 board_build.flash_mode = dout
 custom_description = The historic RF gateway using RCSwitch library
 
@@ -1453,6 +1455,7 @@ build_flags =
   '-DZgatewayRF="RF"'
   '-DZradioCC1101="CC1101"'
   '-DGateway_Name="OMG_ESP8266_RF-CC1101"'
+  '-DvalueAsATopic=true'
 board_build.flash_mode = dout
 custom_description = RF gateway using RCSwitch library with CC1101
 

main/ZgatewayRF.ino

@@ -95,12 +95,14 @@ void RFtoMQTTdiscovery(uint64_t MQTTvalue) {
   String discovery_topic = String(subjectRFtoMQTT);
 #    endif
 
-  String theUniqueId = getUniqueId("-" + String(switchRF[0]), "-" + String(switchRF[1]));
+  String theUniqueId = getUniqueId(String(switchRF[0]), "-" + String(switchRF[1]));
+  String subType = String(switchRF[0]);
 
   announceDeviceTrigger(
       false,
       (char*)discovery_topic.c_str(),
-      "", "",
+      "received",
+      (char*)subType.c_str(),
       (char*)theUniqueId.c_str(),
       "", "", "", "");
 }