in example.c:
-> all leds on when we see a neighbor
-> send publish msg when buttons are pressed

in mqtt-msg.c:
-> comment the data's print in publish msg

in mqtt-service.h:
-> add two functions to publish button state

in mqtt-service.c:
-> implement two functions to publish button state
-> add functions to register to switch1 and switch2
-> handle regack for switch1 and switch2

TODO:
This new code is DIRTY !!!!
It's only for testing with the switch added.
In the future it will be more generic for multiple subscribe and
multiple publish