Support open-haystack(diy airtag) FindMy ble advertisement

[OpenHaystack](https://github.com/seemoo-lab/openhaystack) is a framework for tracking personal Bluetooth devices via Apple's Find My network. You can use it to create your own tracking tags that you can append to physical objects (keyrings, backpacks, car keys, power banks ...) or integrate it into other Bluetooth-capable devices such as notebooks.

After flashing firmwares to esp32/Nordic_nRF5x/Telink_TLSR825X and many other chips/devices, they continuously broadcasts BLE singals in FindMy protocal.

[Some firmwares](https://github.com/acalatrava/openhaystack-firmware) support multiple advertisement keys, so tags with these firmwares will change their MAC address regularly.

It would be greate if bermuda supports tags with openhaystack firmwares.

One more thing, this script [`showmac.py`](https://github.com/pix/heystack-nrf5x/blob/master/tools/showmac.py) can extract MAC addresses from `*.key_file` files generated by [`generate_keys.py`](https://github.com/biemster/FindMy/blob/main/generate_keys.py).