fix(server): limit rootDoc snapshot size (#12625)

close CLOUD-225

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

## Summary by CodeRabbit

- **New Features**
  - Added support for reading document blocks without requiring a workspace or root document snapshot.
- **Bug Fixes**
  - Improved handling of large workspace snapshots by skipping them when they exceed 10MB.
- **Tests**
  - Introduced new test cases to cover scenarios where root or workspace snapshots are absent.
  - Expanded snapshot tests for document block reading.
- **Refactor**
  - Updated several function signatures to make root and workspace snapshot parameters optional for greater flexibility.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/common/reader/__tests__/reader.spec.ts

@@ -35,6 +35,18 @@ test('should read doc blocks work', async () => {
   expect(result).toMatchSnapshot();
 });
 
+test('should read doc blocks work without root doc', async () => {
+  const doc = new YDoc({
+    guid: 'test-doc',
+  });
+  applyUpdate(doc, docSnapshot);
+  const result = await readAllBlocksFromDoc({
+    ydoc: doc,
+    spaceId: 'test-space',
+  });
+  expect(result).toMatchSnapshot();
+});
+
 test('should get all docs from root doc work', async () => {
   const rootDoc = new YDoc({
     guid: 'test-root-doc',