Support paying LNURLpay codes using Tor

[openoms]

Currently the LNURL pay code usage does heavily depend on custodial services running the infrastructure allowing to receive payments all the time and supplying the clearnet domain however the LNURL protocol does support Tor domains as well which make the self-hosted setup easier.
There are no mobile wallets which currently support LNURLs using a Tor address, but to reduce the barrier to entry to self-custodial usage this should be improved.

Changes will be likely necessary in:
The mobile app (this repo) to recognize the onion addresses
https://github.com/GaloyMoney/lnurl-pay - where the LNURL related functions are
https://github.com/GaloyMoney/galoy-pay- to resolve the onion addresses using a Tor proxy

Example LNURL over Tor address and setup with BTCPay: https://gist.github.com/openoms/9be181ffba14afcfb458cd3e1d726b5e