Issue only one OpenFile and CloseFile request per handle

zed/src/rpc.rs

@@ -11,6 +11,7 @@ use std::collections::{HashMap, HashSet};
 use std::time::Duration;
 use std::{convert::TryFrom, future::Future, sync::Arc};
 use surf::Url;
+use zed_rpc::proto::EnvelopedMessage;
 use zed_rpc::{proto::RequestMessage, rest, Peer, TypedEnvelope};
 use zed_rpc::{PeerId, Receipt};
 
@@ -191,6 +192,14 @@ impl Client {
         })
     }
 
+    pub fn send<T: EnvelopedMessage>(
+        &self,
+        connection_id: ConnectionId,
+        message: T,
+    ) -> impl Future<Output = Result<()>> {
+        self.peer.send(connection_id, message)
+    }
+
     pub fn request<T: RequestMessage>(
         &self,
         connection_id: ConnectionId,