refactor(core): minimize comment editor (#12995)

#### PR Dependency Tree


* **PR #12995** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Introduced a new clipboard module, making clipboard-related
functionality available for external use.
* Added a comprehensive extension system for the comment editor,
supporting rich text features, widgets, and configurable options.

* **Bug Fixes**
* Improved stability by ensuring comment highlighting features and
toolbar event subscriptions handle missing dependencies gracefully,
preventing potential runtime errors.

* **Refactor**
* Simplified comment editor view manager setup for easier configuration
and maintenance.

* **Chores**
* Updated package exports to expose new clipboard modules and
configurations.
* Removed confirm modal and portal-related logic from the comment editor
component.
* Adjusted temporary store creation to omit adding an extra surface
block under the root page.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/foundation/src/clipboard.ts

@@ -43,7 +43,7 @@ const imageClipboardConfigs = [
   });
 });
 
-const PlainTextClipboardConfig = ClipboardAdapterConfigExtension({
+export const PlainTextClipboardConfig = ClipboardAdapterConfigExtension({
   mimeType: 'text/plain',
   adapter: MixTextAdapter,
   priority: 70,