remove duplicate code in main\ZgatewayBT.ino (#557)

* merge duplicate code into function setWorBMac

* rename setWorBMac to updateWorB

* add helper getDeviceByMac

* change updateWorB to use helper getDeviceByMac

* change isWhite to use helper getDeviceByMac

* change isBlack to use helper getDeviceByMac

* change isDiscovered to use helper getDeviceByMac

* eliminate duplicate devices walk for isWhite, isBlack and isDiscovered check

* fix a data corruption race between MQTTtoBT and discovery-functions

the ***Discovery functions every time create a new device unless this device is set to white-list before. as a result of this, the devices list contains the same mac multiple times with different flags

* eliminate duplicate devices walk for oneWhite check

because now we have a utility function 'createOrUpdateDevice' we can globally cache this as a single flag

* secure createOrUpdateDevice agains data races on multicore esp32

* fix the concept of the createOrUpdateDevice

c / c++ does not allow NULL as function parameter like modern languages

* use nkolban Semaphore helper class (already included and used from eos1d3/ESP32_BLE librarie)

this makes the semaphore handling more cleaner and readable

* merge duplicate code during createDiscovery into new helper createDiscoveryFromList

* replace excessive use of ZmqttDiscovery precompiler directive in ble advertised callbacks with dummy functions

for a better readability we can remove this because isDiscovered does not do a devices walk anymore

* fix build errors found by travis-ci

main/config_BT.h

@@ -55,6 +55,10 @@ struct BLEdevice{
   bool isBlkL;
 };
 
+#define device_flags_isDisc 1 << 0
+#define device_flags_isWhiteL 1 << 1
+#define device_flags_isBlackL 1 << 2
+
 struct decompose{
   char subject[4];
   int start;