feat(core): completely remove the dependence on EditorHost (#13110)

Close [AI-260](https://linear.app/affine-design/issue/AI-260)

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

* **New Features**
* Added theme support to AI chat and message components, enabling
dynamic theming based on the current app theme.
* Introduced a reactive theme signal to the theme service for improved
theme handling.
* Integrated notification and theme services across various AI chat,
playground, and message components for consistent user experience.

* **Refactor**
* Simplified component APIs by removing dependencies on editor host and
related properties across AI chat, message, and tool components.
* Centralized and streamlined clipboard and markdown conversion
utilities, reducing external dependencies.
* Standardized the interface for context file addition and improved type
usage for better consistency.
* Reworked notification service to a class-based implementation for
improved encapsulation.
* Updated AI chat components to use injected notification and theme
services instead of host-based retrieval.

* **Bug Fixes**
* Improved reliability of copy and notification actions by decoupling
them from editor host dependencies.

* **Chores**
* Updated and cleaned up internal imports and removed unused properties
to enhance maintainability.
  * Added test IDs for sidebar close button to improve test reliability.
  * Updated test prompts in end-to-end tests for consistency.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/shared/src/services/notification-service.ts

@@ -40,7 +40,6 @@ export interface NotificationService {
     }[];
     onClose?: () => void;
   }): void;
-
   /**
    * Notify with undo action, it is a helper function to notify with undo action.
    * And the notification card will be closed when undo action is triggered by shortcut key or other ways.
@@ -55,13 +54,16 @@ export const NotificationProvider = createIdentifier<NotificationService>(
 );
 
 export function NotificationExtension(
-  notificationService: Omit<NotificationService, 'notifyWithUndoAction'>
+  notificationService: NotificationService
 ): ExtensionType {
   return {
     setup: di => {
       di.addImpl(NotificationProvider, provider => {
         return {
-          ...notificationService,
+          notify: notificationService.notify,
+          toast: notificationService.toast,
+          confirm: notificationService.confirm,
+          prompt: notificationService.prompt,
           notifyWithUndoAction: options => {
             notifyWithUndoActionImpl(
               provider,