Electron and NodeJS C++ addon support

[hsjoberg]

This actually works. https://github.com/hsjoberg/node-addon-lnd
You can create a NodeJS C++ addon that also talks to the CGO falafel bindings.
This can then be used to create a react-native app for Linux using Electron and react-native-web.

The NodeJS C++ addon needs to expose the same core API as the C++ TurboModule.

When using Electron Forge, it will automatically compile the NodeJS C++ addon for Electron env by just reading the lib's binding.gyp file.

[hsjoberg]

One unanswered question is if we should have a helper to expose all gRPC methods to the electron bridge. Otherwise the user has to set this up themselves.