[SYS] Externalize utils function keep cmpToMainTopic (#2048)

And fill generateHash

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

main/ZcommonRF.ino

@@ -301,7 +301,7 @@ void RFConfig_load() {
 }
 
 void MQTTtoRFset(char* topicOri, JsonObject& RFdata) {
-  if (TheengsUtils::cmpToMainTopic(topicOri, subjectMQTTtoRFset)) {
+  if (cmpToMainTopic(topicOri, subjectMQTTtoRFset)) {
     Log.trace(F("MQTTtoRF json set" CR));
 
     /*