Dynamic list of MAC addresses

[Emanuel Regnath]

The list of authorized and configured Dash-Buttons should be managed in a dynamic list instead of a if construct. On button press, an individual function should iterate over the list and check if the MAC is known and if a button press for this MAC was detected before for the same poll (prevent double-voting).

Refer to https://github.com/tum-ei-esi/dash-back/blob/6e0b92f25ed33d33977a3566b338eaf1229e0009/ledcontrol.py#L22-L42

Python lists: https://docs.python.org/3/tutorial/datastructures.html