Versioning support

When you interact with files on the web interface, you get versioning of the files you work against. Edit a file? New version. Upload a modified copy of a file that already exists? New version.

When you use the desktop sync app, this functionality is broken. New versions aren't made when you modify files synced with desktop apps, and you also can't restore through the desktop app.

We need the desktop app to be extended to at least create new versions of files when modifications happen. Extending this further with the ability to interact with versions in the desktop UX would be even more valuable. And I'm not just saying Windows, I mean any OS the desktop client runs on.

I think this is one of the last items to really enable nextCloud to go toe to toe with things like OneDrive and others.

Please?