[Folder nesting] Support folder nesting

[cedvdb]

Same as the file nesting feature but for folders. This would be helpful for example in flutter apps where to root directory looks like the following:

flutter_project
├── .github
├── .vscode
├── android
├── assets
├── docs
├── example
├── ios
├── lib
├── linux
├── macos
├── test
├── test_driver
├── integration_test
├── web
├── windows
├── pubspec.yaml
├── pubspec.lock

I'd like to make my folders look like the following:

flutter_project
├── .github
├── .vscode
├── assets
├── docs
├── example
├── lib
├── platforms
│   ├── android
│   ├── linux
│   ├── macos
│   ├── web
│   ├── windows
│   ├── macos
├── testing
│   ├── test_driver
│   ├── integration_test
│   ├── test

[vs-code-engineering[bot]]

This feature request is now a candidate for our backlog. The community has 60 days to upvote the issue. If it receives 20 upvotes we will move it to our backlog. If not, we will close it. To learn more about how we handle feature requests, please see our documentation.

Happy Coding!