cln: replace glightning socket api with grpc api

[JssDWt]

In this PR the client used to connect to cln is replaced with grpc.
Previously we would connect to the cln api through glightning, using the lightning-rpc socket file.
Replacing with grpc has several advantages:

• Breaking changes in the core lightning api will be reflected in the protos -> We have the advantage of code generation for client calls.
• Adding calls to cln is easier, because we don't have to modify glightning to add functions or fields
• This setup is better suited for container deployments

This is a breaking change!

The glightning socket api was removed and replaced with the grpc one.

LSPD's NODES configuration has changed to contain grpc addresses and certficates. Note the certficates can be either a file path or a raw certificate.

[hydra-yse]

LGTM