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 -->

packages/frontend/core/src/blocksuite/ai/utils/editor-actions.ts

@@ -1,5 +1,6 @@
-import { deleteTextCommand } from '@blocksuite/affine/inlines/preset';
+import { WorkspaceImpl } from '@affine/core/modules/workspace/impls/workspace';
 import { defaultImageProxyMiddleware } from '@blocksuite/affine/shared/adapters';
+import { replaceSelectedTextWithBlocksCommand } from '@blocksuite/affine/shared/commands';
 import { isInsideEdgelessEditor } from '@blocksuite/affine/shared/utils';
 import {
   type BlockComponent,
@@ -8,7 +9,12 @@ import {
   SurfaceSelection,
   type TextSelection,
 } from '@blocksuite/affine/std';
-import { type BlockModel, Slice } from '@blocksuite/affine/store';
+import {
+  type BlockModel,
+  type BlockSnapshot,
+  Slice,
+} from '@blocksuite/affine/store';
+import { Doc as YDoc } from 'yjs';
 
 import {
   insertFromMarkdown,
@@ -109,19 +115,53 @@ export const replace = async (
   );
 
   if (textSelection) {
-    host.std.command.exec(deleteTextCommand, { textSelection });
-    const { snapshot, transformer } = await markdownToSnapshot(
-      content,
-      host.store,
-      host
-    );
-    if (snapshot) {
-      await transformer.snapshotToSlice(
-        snapshot,
-        host.store,
-        firstBlockParent.model.id,
-        firstIndex + 1
+    const collection = new WorkspaceImpl({
+      id: 'AI_REPLACE',
+      rootDoc: new YDoc({ guid: 'AI_REPLACE' }),
+    });
+    collection.meta.initialize();
+    const fragmentDoc = collection.createDoc();
+
+    try {
+      const fragment = fragmentDoc.getStore();
+      fragmentDoc.load();
+
+      const rootId = fragment.addBlock('affine:page');
+      fragment.addBlock('affine:surface', {}, rootId);
+      const noteId = fragment.addBlock('affine:note', {}, rootId);
+
+      const { snapshot, transformer } = await markdownToSnapshot(
+        content,
+        fragment,
+        host
       );
+
+      if (snapshot) {
+        const blockSnapshots = (
+          snapshot.content[0].flavour === 'affine:note'
+            ? snapshot.content[0].children
+            : snapshot.content
+        ) as BlockSnapshot[];
+
+        const blocks = (
+          await Promise.all(
+            blockSnapshots.map(async blockSnapshot => {
+              return await transformer.snapshotToBlock(
+                blockSnapshot,
+                fragment,
+                noteId,
+                0
+              );
+            })
+          )
+        ).filter(block => block) as BlockModel[];
+        host.std.command.exec(replaceSelectedTextWithBlocksCommand, {
+          textSelection,
+          blocks,
+        });
+      }
+    } finally {
+      collection.dispose();
     }
   } else {
     selectedModels.forEach(model => {