* 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
Peter Becker
033a583f0a