Implement a more robust IPC system between the launcher and client (#4159)

* Implement a more robust IPC system between the launcher and client

* Clippy fix and cargo fmt

* Switch to cached JsonReader with LENIENT parsing to avoid race conditions

* Make RPC send messages in lines

* Try to bind to either IPv4 or IPv6 and communicate version

* Move message handling into a separate function to avoid too much code in a macro

packages/app-lib/src/util/network.rs

@@ -0,0 +1,17 @@
+use std::io;
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
+use tokio::net::TcpListener;
+
+pub async fn tcp_listen_any_loopback() -> io::Result<TcpListener> {
+    // IPv4 is tried first for the best compatibility and performance with most systems.
+    // IPv6 is also tried in case IPv4 is not available. Resolving "localhost" is avoided
+    // to prevent failures deriving from improper name resolution setup. Any available
+    // ephemeral port is used to prevent conflicts with other services. This is all as per
+    // RFC 8252's recommendations
+    const ANY_LOOPBACK_SOCKET: &[SocketAddr] = &[
+        SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 0),
+        SocketAddr::new(IpAddr::V6(Ipv6Addr::LOCALHOST), 0),
+    ];
+
+    TcpListener::bind(ANY_LOOPBACK_SOCKET).await
+}