fix: bubble exports (#7189)

* fix: bubble exports

* chore: delete the old bubble

core/bubbles.ts

@@ -0,0 +1,12 @@
+/**
+ * @license
+ * Copyright 2023 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {Bubble} from './bubbles/bubble.js';
+import {TextBubble} from './bubbles/text_bubble.js';
+import {TextInputBubble} from './bubbles/textinput_bubble.js';
+import {MiniWorkspaceBubble} from './bubbles/mini_workspace_bubble.js';
+
+export {Bubble, TextBubble, TextInputBubble, MiniWorkspaceBubble};