sourcemap service improvements

• If you disable sourcemaps with webpack then the cli will still translate any file if the sourcemap is present.
  the cli sourcemap service should be disable when env.sourcemap is false. I found myself in the need to see the actual source files from an error. I simply couldnt, had to modify the cli code to disable the sourcemap entirely
• when translating source maps the cli always adds "app" at the start as file name. This is wrong. It should only do that when it is an actual app file.

从 CLI sourcemap 服务入手，检查 env.sourcemap 和已翻译文件名的处理方式。在禁用 sourcemap 以及处理非应用文件时验证行为；完成标准是：禁用 sourcemap 时服务不会进行翻译，并且只在适当的情况下添加 "app" 前缀。