refactor(editor): cleanup dead code (#12072)

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

- **Refactor**
  - Simplified and removed several internal AI block extension files and utility functions, streamlining the codebase and reducing unused features.
  - Updated logic to access editor modes and controllers directly, removing reliance on DOM queries and certain abstractions.
  - Reduced and restructured effect type declarations for improved clarity.

- **Bug Fixes**
  - Improved type safety in the editor component by explicitly typing queried elements.

- **Chores**
  - Removed obsolete exports and internal functions with no impact on user-facing functionality.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

tests/blocksuite/e2e/utils/declare-test-window.ts

@@ -1,14 +1,14 @@
-import type * as Effects from '@blocksuite/affine/effects';
-import type * as ConnectorToolEffect from '@blocksuite/affine/gfx/connector';
-import type * as ShapeToolEffect from '@blocksuite/affine/gfx/shape';
+import type * as Effect from '@blocksuite/affine/effects';
+import type * as ConnectorEffect from '@blocksuite/affine/gfx/connector';
+import type * as ShapeEffect from '@blocksuite/affine/gfx/shape';
 import type { EditorHost } from '@blocksuite/affine/std';
 import type { Store, Transformer, Workspace } from '@blocksuite/affine/store';
 import type { TestAffineEditorContainer } from '@blocksuite/integration-test';
 
-declare const _GLOBAL_:
-  | typeof Effects
-  | typeof ConnectorToolEffect
-  | typeof ShapeToolEffect;
+declare type _GLOBAL_ =
+  | typeof Effect
+  | typeof ConnectorEffect
+  | typeof ShapeEffect;
 
 declare global {
   interface Window {

tests/kit/src/utils/editor.ts

@@ -1,12 +1,11 @@
-import type * as BlocksuiteEffects from '@blocksuite/affine/effects';
+import '@blocksuite/affine/effects';
+
 import type { IVec, XYWH } from '@blocksuite/affine/global/gfx';
 import type { CodeBlockComponent } from '@blocksuite/affine-block-code';
 import type { ParagraphBlockComponent } from '@blocksuite/affine-block-paragraph';
 import type { BlockComponent } from '@blocksuite/std';
 import { expect, type Locator, type Page } from '@playwright/test';
 
-declare type _GLOBAL_ = typeof BlocksuiteEffects;
-
 const EDGELESS_TOOLBAR_WIDGET = 'edgeless-toolbar-widget';
 export const ZERO_WIDTH_FOR_EMPTY_LINE =
   process.env.BROWSER === 'webkit' ? '\u200C' : '\u200B';