Enhancement: Toggle for allowing access to GVFS filesystems

[ghost]

There could be a toggle for allowing apps to access each GVFS file system and for allowing access to all of them.

I know you can add the GVFS locations manually in Flatseal to give access, but this should be a built-in option since we often need to give Flatpak apps' permission to access network file systems.

My use-case for this is that I need to give apps access to my GVFS-GOA nextcloud storage.