Propose and implement hardware reset of firmware

[mariobehling]

As there are more and more options to configure the firmware we should also have a way to reset the firmware to factory settings / default config directly on the badge. An example would be pressing both buttons for 10 seconds or so. What do you think would be a suitable way. If possible the badge would show a screen with the reset info as well.

[froscon2024]

Yes, that would be great to be able to reset the badge on the go without any need of additional hardware to do so.