nrf24mousejacker : add keyboard layout selection using UP/DOWN

[OuinOuin74]

for now there is 13 most used layout but it's easy to add more

[Willy-JL]

ill have to look better at the code but like the overall idea. might be even better to load layouts from file, should be fairly trivial as they are just a binary blob that you can then point the app to use after it is read from file. that way, can just use layouts included with badusb