fix(core): ai replace selection (#11875)

### TL;DR

* Fix the issue of inaccurate content replacement in AI Replace Selection
* Optimize unit Tests utils

### What Changed
1. Fixed the issue of inaccurate content replacement in AI Replace Selection:
  - Convert the AI Answer into a Snapshot, then transform it into a sequence of Blocks ready for insertion.
   - Invoke the `replaceSelectedTextWithBlocks` command to replace the current selection with blocks (given the complexity of block combinations, this command uses [ts-pattern](https://github.com/gvergnaud/ts-pattern) implementation to ensure compile-time prevention of pattern handling omissions).
2. Optimized unit test assertions for commands, now allowing direct document content comparison using `toEqualDoc`.
```ts
const host = affine`
  <affine-page id="page">
    <affine-note id="note">
      <affine-paragraph id="paragraph-1">Hel<anchor />lo</affine-paragraph>
      <affine-paragraph id="paragraph-2">Wor<focus />ld</affine-paragraph>
    </affine-note>
  </affine-page>
`;

// ....

const expected = affine`
  <affine-page id="page">
    <affine-note id="note">
      <affine-paragraph id="paragraph-1">Hel111</affine-paragraph>
      <affine-code id="code"></affine-code>
      <affine-paragraph id="paragraph-2">222ld</affine-paragraph>
    </affine-note>
  </affine-page>
`;

expect(host.doc).toEqualDoc(expected.doc);
```
3. Added support for text cursors in unit test template syntax.

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

> CLOSE BS-3278

- **New Features**
  - Introduced the ability to replace selected text in documents with blocks, supporting advanced merging and insertion scenarios for various block types.
- **Bug Fixes**
  - Improved handling of text selection and cursor placement in document templates used for testing.
- **Tests**
  - Added comprehensive tests for replacing selected text with blocks, including edge cases and complex selection scenarios.
  - Enhanced test utilities for document structure comparison and selection handling.
  - Updated end-to-end tests to verify correct replacement of selected text via AI-driven actions.
- **Chores**
  - Added and updated dependencies to support new features.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

tests/affine-cloud-copilot/e2e/chat-with/text.spec.ts

@@ -1,3 +1,4 @@
+import { IS_MAC } from '@blocksuite/global/env';
 import { expect } from '@playwright/test';
 
 import { test } from '../base/base-test';
@@ -62,13 +63,22 @@ test.describe('AIChatWith/Text', () => {
     loggedInPage: page,
     utils,
   }) => {
-    const { translate } = await utils.editor.askAIWithText(page, 'Apple');
-    const { answer } = await translate('German');
-    await expect(answer).toHaveText(/Apfel/, { timeout: 10000 });
+    await utils.editor.focusToEditor(page);
+    await page.keyboard.insertText('I Loev Apple');
+
+    // Select the word "Loev"
+    const SHORT_KEY = IS_MAC ? 'Alt' : 'Control';
+    await page.keyboard.press(`${SHORT_KEY}+ArrowLeft`);
+    await page.keyboard.press('ArrowLeft');
+    await page.keyboard.press(`Shift+${SHORT_KEY}+ArrowLeft`);
+
+    const { fixSpelling } = await utils.editor.showAIMenu(page);
+    const { answer } = await fixSpelling();
+    await expect(answer).toHaveText(/Love/, { timeout: 10000 });
     const replace = answer.getByTestId('answer-replace');
     await replace.click();
     const content = await utils.editor.getEditorContent(page);
-    expect(content).toBe('Apfel');
+    expect(content).toBe('I Love Apple');
   });
 
   test('should support continue in chat', async ({

tests/affine-cloud-copilot/e2e/utils/editor-utils.ts

@@ -546,19 +546,7 @@ export class EditorUtils {
     };
   }
 
-  public static async askAIWithText(page: Page, text: string) {
-    await this.focusToEditor(page);
-    const texts = text.split('\n');
-    for (const [index, line] of texts.entries()) {
-      await page.keyboard.insertText(line);
-      if (index !== texts.length - 1) {
-        await page.keyboard.press('Enter');
-      }
-    }
-    await page.keyboard.press('ControlOrMeta+A');
-    await page.keyboard.press('ControlOrMeta+A');
-    await page.keyboard.press('ControlOrMeta+A');
-
+  public static async showAIMenu(page: Page) {
     const askAI = await page.locator('page-editor editor-toolbar ask-ai-icon');
     await askAI.waitFor({
       state: 'attached',
@@ -661,6 +649,22 @@ export class EditorUtils {
     } as const;
   }
 
+  public static async askAIWithText(page: Page, text: string) {
+    await this.focusToEditor(page);
+    const texts = text.split('\n');
+    for (const [index, line] of texts.entries()) {
+      await page.keyboard.insertText(line);
+      if (index !== texts.length - 1) {
+        await page.keyboard.press('Enter');
+      }
+    }
+    await page.keyboard.press('ControlOrMeta+A');
+    await page.keyboard.press('ControlOrMeta+A');
+    await page.keyboard.press('ControlOrMeta+A');
+
+    return await this.showAIMenu(page);
+  }
+
   public static async whatAreYourThoughts(page: Page, text: string) {
     const textarea = page.locator(
       'affine-ai-panel-widget .ai-panel-container textarea'