Display generated bg in the bg block. Add ability to copy chat bg to system list.

public/script.js

@@ -7721,6 +7721,7 @@ jQuery(async function () {
                 $("#rm_button_selected_ch").children("h2").text('');
                 select_rm_characters();
                 sendSystemMessage(system_message_types.WELCOME);
+                eventSource.emit(event_types.CHAT_CHANGED, getCurrentChatId());
             } else {
                 toastr.info("Please stop the message generation first.");
             }