Add Mac address to device_trackers in config entry

as in discussion Add Mac address to Asus device config panel · Discussion #9164 · home-assistant/frontend · GitHub

please consider adding the MAC address of the given devices in the device info panel, to allow us to distinguish the various automatically created trackers, and to match them with the devices we have in the router.

right now we have various trackers, sometimes multiple ones with a suffix _2, _3, and it requires hacking the .storage files to be able to see which is which (Mac address is available there)