fix: stop byte-fiddling the utp connection ID

Trust that the utp library returns the connection ID in its preferred
format. Stop swapping to and from big-endian.

I am still working out why this wasn't causing any problems up until the
(still pending) RFC refactor. After the refactor, the connection IDs
diverge on the outbound and inbound sides, which causes the utp
transmission to fail.

portalnet/src/overlay/protocol.rs

@@ -466,7 +466,6 @@ where
                     Content::Enrs(_) => Ok((found_content, false)),
                     // Init uTP stream if `connection_id` is received
                     Content::ConnectionId(conn_id) => {
-                        let conn_id = u16::from_be(conn_id);
                         let content = self.init_find_content_stream(enr, conn_id).await?;
                         match self.validate_content(&content_key, &content).await {
                             Ok(_) => Ok((Content::Content(content), true)),

portalnet/src/overlay/service.rs

@@ -967,8 +967,7 @@ where
                         drop(permit);
                     });
 
-                    // Connection id is sent as BE because uTP header values are stored also as BE
-                    Ok(Content::ConnectionId(cid_send.to_be()))
+                    Ok(Content::ConnectionId(cid_send))
                 }
             }
             // If we don't have data to send back or can't obtain a permit, send the requester a
@@ -1232,7 +1231,7 @@ where
         });
 
         let accept = Accept {
-            connection_id: cid_send.to_be(),
+            connection_id: cid_send,
             content_keys: requested_keys,
         };
 
@@ -1457,7 +1456,7 @@ where
         }
 
         // Build a connection ID based on the response.
-        let conn_id = u16::from_be(response.connection_id);
+        let conn_id = response.connection_id;
         let cid = utp_rs::cid::ConnectionId {
             recv: conn_id,
             send: conn_id.wrapping_add(1),
@@ -1676,7 +1675,6 @@ where
                     Content::Enrs(_) => return Err(anyhow!("expected content, got ENRs")),
                     // Init uTP stream if `connection_id` is received
                     Content::ConnectionId(conn_id) => {
-                        let conn_id = u16::from_be(conn_id);
                         let cid = utp_rs::cid::ConnectionId {
                             recv: conn_id,
                             send: conn_id.wrapping_add(1),