[feature] mark/deprioritize generated files by default in Tree View

When reviewing pull requests in GitHub web UI, it does a great job of collapsing/hiding generated content by default:

Users can do so by adding linguist-generated to these files .gitattributes as shown here: https://docs.github.com/en/repositories/working-with-files/managing-files/customizing-how-changed-files-appear-on-github

However, this experience does not translate well into VS Code, either from the desktop editor, or the www.github.dev UI.
I suggest graying out these entries as well in:

1. The "Source Control" container (local changes tree view)
2. The "Github Pull Request" container (active PR tree view)
3. The active text editor file name (title).
4. Possibly collapse these files/folder trees by default.

This seems to be possible via the new FileDecorationProvider VS Code API: https://code.visualstudio.com/api/references/vscode-api#FileDecorationProvider

This is especially important in projects that rely on code generation, where pull requests can contain a single file (source change), and many (tens) of other affected/generated files.

Any thoughts/suggestions welcomed.

从 FileDecorationProvider API 开始，检查 Source Control 和 GitHub Pull Request 树视图，以及活动编辑器标题的行为。完成的标准是：在所请求的界面中，标记为 linguist-generated 的文件在视觉上被降低优先级；分别确定默认折叠树是否可行。