Give indication of starting exit process

Particularly if recording the session, exit no longer is instant.  Provide feedback to user that the exit process is being worked.

confluent_client/bin/nodeconsole

@@ -414,6 +414,7 @@ class InputHandler:
             await relay_keypresses(self.buffer[3:], modifiers=[SpecialKeys.ALT, SpecialKeys.SYSRQ])
             self.reset_input_context()
         elif self.buffer == '\x05c.' or self.buffer == '\x05cq':  # Ctrl-E, then . or q
+            set_extra_text('Exiting...') 
             asyncio.get_running_loop().call_soon(sys.exit, 0)
             return
         elif self.buffer == '\x05cf':  # Ctrl-E, then c, then f