Delete empty folders in clean operation up to the start destination folder.

[YangLyu89]

Minimal repro steps

1. Have a libman.json file with the content like { "version": "1.0", "defaultProvider": "cdnjs", "libraries": [ { "destination": "wwwroot/lib/jquery/", "library": "[email protected]" } ] }
2. Restore client-side libraries
3. Clean client-side libraries

The wwwroot folder will be deleted

We can probably keep a record of the wwwroot folder here. Or if starting on UI by right click on wwwroot, and adding client-side library, do the same. So we can remain the wwwroot empty folder.

[jodavis]

We're not sure if this change in behavior is necessary.