Removed room from chat

- Uses the global room instead of adding and leaving room for users
- Removes the joining event and triggers connection status from
server as soon as a connection event is received in server side

cli/onionshare_cli/mode_settings.py

@@ -56,7 +56,7 @@ class ModeSettings:
                 "disable_files": False,
             },
             "website": {"disable_csp": False, "filenames": []},
-            "chat": {"room": "default"},
+            "chat": {},
         }
         self._settings = {}