Possibility of Malt Node Tree "Sub-Panels"?

[dibli-goost]

A new addition in Blender 4.0 is Sub Panels for use in node groups, and on the Principled BSDF. https://projects.blender.org/blender/blender/issues/108895

Seems like a good idea to get this into Malt as well. Don't know if any of the existing nodes actually need it. But with my habit of creating Mega-Shaders of my own... It would be very useful!

Not sure what the best way to go about defining them in the "Meta" code blocks would be. Perhaps something like so?

/* META
    @a1: subpanel=Panel A;
    
    @a2: subpanel=Panel A;
    
    @b1: subpanel=Panel B;
    
    @b2: subpanel=Panel B;

    @a3 subpanel=Panel A;
*/

Use the top down sorting the same way that is currently done with the parameters. First defined panel shows up first on the node, and so on. With the case of a3, where it shows up later, It could be appended to the end of Panel A, and so on for any future occurrence of that subpanel.