Create an LDK-RPC project

[bjohnson5]

Create a new rust library crate (outside of BLAST) that is a GRPC server for ldk-node. Make it simple to add to and ldk-node project (import it just like you have to import ldk-node). That way anyone who is using the ldk-node crate can also just import ldk-rpc and pass the ldk-node object to the constructor to spin up a GRPC server for their node.

• Use TLS authentication
• Use this crate in BLAST to add RPC capabilities to blast_ldk
• Use this crate in simln to add LDK support