feat(server): comment model (#12760)

close CLOUD-226

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

- **New Features**
- Introduced support for comments and replies within workspaces and
documents, enabling users to create, update, delete, and resolve
comments, as well as manage threaded replies.
- **Bug Fixes**
- Added user-friendly error messages and handling for situations where
comments or replies are not found.
- **Tests**
- Added comprehensive tests to ensure correct behavior of comment and
reply operations.
- **Localization**
  - Added English translations for new comment and reply error messages.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->














#### PR Dependency Tree


* **PR #12760** 👈
  * **PR #12909**
    * **PR #12911**
      * **PR #12761**
        * **PR #12924**
          * **PR #12925**

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

packages/backend/server/src/models/index.ts

@@ -7,6 +7,7 @@ import {
 import { ModuleRef } from '@nestjs/core';
 
 import { ApplyType } from '../base';
+import { CommentModel } from './comment';
 import { AppConfigModel } from './config';
 import { CopilotContextModel } from './copilot-context';
 import { CopilotJobModel } from './copilot-job';
@@ -48,6 +49,7 @@ const MODELS = {
   copilotWorkspace: CopilotWorkspaceConfigModel,
   copilotJob: CopilotJobModel,
   appConfig: AppConfigModel,
+  comment: CommentModel,
 };
 
 type ModelsType = {
@@ -99,6 +101,7 @@ const ModelsSymbolProvider: ExistingProvider = {
 })
 export class ModelsModule {}
 
+export * from './comment';
 export * from './common';
 export * from './copilot-context';
 export * from './copilot-job';