Added node comms

node/src/comms.rs

@@ -0,0 +1,17 @@
+pub trait Sender {
+    async fn send(&mut self, msg: &[u8]) -> Result<(), Reset>;
+}
+
+pub trait Receiver {
+    async fn receive(&mut self, buffer: &mut [u8]) -> Result<(), Reset>;
+}
+
+//TODO: Replace with !
+pub struct Never;
+
+/// Communication errors indicates either:
+/// Our connection was already disconnected, in which case we should reset and wait for new connection to made.
+/// or
+/// There was an unexpected, irrecoverable error in communication, in which case we don't want to enter a terminal error
+/// safe mode, because there is no indication the actual control is broken, so all we can really do is reset the connection.
+pub struct Reset;