[Feature] file_manager web

[yonacwy]

A nice feature would be file_manager for web sandboxed, although access to a full file system is limited still able to expose the app dir through the local network. Plus this method is web server (dart) and client (flutter) in order for it to work, similar to zapp.run sandboxing but the file_manager.

Ill add it to my fork/branch seeing i didn't work from the fork when i started.