Add description to switch devices

[johnnyasantoss]

This way we can have a backend customizable field instead of hardcoding names/labels for the switches.

We are using this in our Draft beer dispenser. Each button on the screen, is a different switch on our lnbits instance. You can check the code here: https://github.com/CasaVinteUm/BitChopp

[dni]

the lnurldevices is in the process of beeing updated into bitcoinswitch/lnpos/fossa extensions i think you may want to target the bitcoinswitch repo? https://github.com/lnbits/bitcoinswitch_extension