fix: exit client on empty rcv (#1535)

* Exit client on empty ipc receive

This resolves a hang when the server goes away unnoticed (e.g. when it
is killed). In some cases, this delayed system shutdown because the
client did not react to systemd's SIGTERM.

* Add newline after error report to tidy up shell prompt

* Update changelog

CHANGELOG.md

@@ -15,6 +15,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 * chore(dependencies): update  `clap`: `3.1.18` -> `3.2.2` (https://github.com/zellij-org/zellij/pull/1496)
 * add: capability to dispatch actions from the cli (https://github.com/zellij-org/zellij/pull/1265)
   Can be invoked through `zellij action [ACTIONS]`.
+* fix: client hang when server is killed / shutdown delay (https://github.com/zellij-org/zellij/pull/1535)
 
   Automatically sends the action to the current session, or if there is just one
   to the single session, if there are multiple sessions, then the session name

zellij-client/src/lib.rs

@@ -297,6 +297,12 @@ pub fn start_client(
                             .send(ClientInstruction::UnblockInputThread)
                             .unwrap();
                         log::error!("Received empty message from server");
+                        send_client_instructions
+                            .send(ClientInstruction::Error(
+                                "Received empty message from server".to_string(),
+                            ))
+                            .unwrap();
+                        break;
                     },
                 }
             }
@@ -309,7 +315,7 @@ pub fn start_client(
         let restore_snapshot = "\u{1b}[?1049l";
         os_input.disable_mouse();
         let error = format!(
-            "{}\n{}{}",
+            "{}\n{}{}\n",
             restore_snapshot, goto_start_of_last_line, backtrace
         );
         let _ = os_input