Adding explicit cloud drive (OneDrive, iCloud Drive) support

A while ago I discovered an issue, whereby Blender accidentally triggered the download of so-called OneDrive on-demand files. ( T87621 ).

This issue exposed the fact that Blender currently isn't particularly cloud storage aware. Now, this isn't a problem perse. Many applications aren't cloud storage aware and work just fine. Often dealing with cloud storage just happens automagically. A large reason for this is that both Windows and macOS now consider their respective cloud storage solutions, OneDrive and iCloud Drive, part of the operating system. They offer official APIs for dealing with their cloud storage (which are also open for third-party cloud storage integration). Another reason is the on-demand downloading of cloud storage files, where files that aren't synced locally are transparently downloaded when an application tries to access them. And lastly, many applications use the operating system's default file dialogs, which offer integrations for almost all available cloud storage solutions, both native and third-party.

Now, Blender doesn't use the system file dialogs, but uses its own file dialog system. This certainly has its advantages, but like Peter Parker's uncle Ben once said: "With great power comes great responsibility". When the system's own file dialogs now offer built-in support for their native cloud storage, should Blender adopt some of this? Or more generic: should Blender be more cloud-storage aware?

Things that come to mind:

• Adding the system cloud storage solution (and detected third-party solutions) as a special favorite/shortcut in the File Dialog navigation bar.

• Show the status of cloud storage files in file dialogs (i.e. a grayed-out look and/or a cloud icon for non-local/placeholder files).

• Offers ways to explicitly trigger cloud storage downloads (and possible the reverse: triggering uploads/cleaning up storage).

• Add support for popular non system-native cloud storage solutions (Google Drive / Dropbox / Box).

I wonder what the Blender community thinks of this.