feat: add remote actor support

[tqwewe]

Adds support for registering/looking up actors in a distributed system, and messaging actors remotely, built on top of libp2p.

The distributed system can be run with:

Actor

#[derive(Actor, RemoteActor)] 
pub struct MyActor { 
    count: i64, 
} 
 
#[derive(Serialize, Deserialize)] 
pub struct Inc { 
    amount: u32, 
} 
 
#[remote_message("3b9128f1-0593-44a0-b83a-f4188baa05bf")] 
impl Message<Inc> for MyActor { 
    type Reply = i64; 
 
    async fn handle(&mut self, msg: Inc, _ctx: Context<'_, Self, Self::Reply>) -> Self::Reply { 
        println!("incrementing"); 
        self.count += msg.amount as i64; 
        self.count 
    } 
}

Node 1

ActorSwarm::bootstrap("127.0.0.1:8000".parse()?)?;

let actor_ref = kameo::spawn(MyActor);
actor_ref.register("my_actor").await?;

Node 2

let swarm = ActorSwarm::bootstrap("127.0.0.1:8001".parse()?)?;
swarm.add_peer_address(PeerId::random(), "127.0.0.1:8000".parse()?).await?;

let actor_ref = RemoteActorRef::<MyActor>::lookup("my_actor").await?;
actor_ref.ask(&Inc { amount: 10 }).send().await?;

[xingsongs]

👍👍👍