Throw an error if client builds retain references to `*.server.ts` files

### Command

build

### Description

When SSR is enabled in an Angular project, there are a few `.server.ts` files produced (e.g. `app.config.server.ts`). The `.server.ts` suffix is also used by different applications as a way to structure and separate client and server code.

The proposal is to update the build pipeline to throw an error in case files with `.server.ts` suffix are present in the final client build output.

// cc @alan-agius4

從 Angular CLI build 命令開始，追蹤啟用 SSR 時最終客戶端 build 輸出的產生方式。驗證 `.server.ts` 檔案如何保留在該輸出中；當存在此類檔案時，build 都回報錯誤即表示完成。

由索引模型根據 Issue 內容生成。