Feature: handle LND restarts

[AndySchroder]

Restarting LND causes LNDK to hang or crash with the following in the log:

thread 'tokio-runtime-worker' panicked at /LNDK/lndk/src/onion_messenger.rs:210:18:
peer subscription failed: Status { code: Unknown, message: "connection error: unexpected end of file", source: Some(hyper::Error(Io, Kind(UnexpectedEof))) }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

If it doesn't crash, then I get a bunch of

2024-10-10T10:02:29.720894896-04:00 TRACE ldk - Failed to find path when sending OffersMessage

messages and things don't work until I manually restart LNDK.

Would be nice for it to auto reconnect instead when LND comes back up, or at the bare minimum, always crash instead of sometimes hang so that you can use systemd to auto restart LNDK if it does crash.

[orbitalturtle]

Ah interesting. To help with this, it might be worth trying to bring #100 back to life :)

Thanks for all the issue reports btw @AndySchroder. I've been a bit swamped but I hope we'll be able to clean up some of these things soon.