lnd: prepare for netns and bring in line with clightning

- Adds bitcoind-host, and tor-socks options to allow using with
  network namespaces.
- Adds listen, rpclisten, and restlisten option to specify host on which
  to listen on for peer, rpc and rest connections respectively
- Adds announce-tor option and generates Tor Hidden Service with nix
  instead of lnd to bring in line with clightning.

WARNING: Breaking changes for Tor Hidden Service. Manual migration
necessary.

examples/configuration.nix

@@ -47,6 +47,10 @@
   # Disable clightning and uncomment the following line in order to enable lnd,
   # a lightning implementation written in Go.
   # services.lnd.enable = true;
+  # Enable this option to announce our Tor Hidden Service. By default lnd
+  # offers outgoing functionality, but doesn't announce the Tor Hidden Service
+  # under which peers can reach us.
+  # services.lnd.announce-tor = true;
   ## WARNING
   # If you use lnd, you should manually backup your wallet mnemonic
   # seed. This will allow you to recover on-chain funds. You can run the