Add simple export option

[Atulin]

Export to Unreal/Unity/Godot is great, but sometimes I need just the textures. Or even a single texture.

I often use MM to generate multiple noises, patterns, shapes, and just pack them into RGBA channels. For projects like that, I would ideally like to export just a single .png representing the albedo

[karmaral]

You can do that within the Preview2D:

That button could probably benefit from an "Export" label though.

[NotArme]

This workaround does work if you need a single image, but it doesn't work as well if you need more than one texture, plus the current export node already feels kinda clunky since there is no way to use them without exporting extra unreal/unity/godot textures which you might not want or need
Relying on the preview2d also means you'd need to manually locate the final node in the chain and export it individually after any changes, which isn't ideal imo

Adding a "Simple export" option that only exports textures from export nodes would not be harmful and would greatly improve pretty much every workflow that doesn't fit perfectly on the current export options