wayland-protocols needs replacement for XDS dnd file saving protocol

We need a wayland equivalent protocol to replace XDS (https://freedesktop.org/wiki/Specifications/XDS/)

XDS support is currently broken between File roller and Nautilus under Wayland (see issue).

Having a Direct Save Dnd protocol is useful for more applications apart from file-roller, GIMP also had support for this, which let you drag the image from inside GIMP over a Nautilus directory and be saved there (this is now broken on wayland). Thanks to XDS you could also drag a file from inside file-roller and drop it over Gedit and be opened for editing (relevant commit).

About the protocol:
Basically, we just need the drag target to be able to communicate a path (or list of paths) to the drag source, the drag source will then transfer the files and communicate when it's finished to the drag target (as the target app may want to open the files after that).

Can this be done as an extension over the current wayland dnd protocol? or maybe needs a separate wayland protocol?