Not sure what you are trying to do but drag&drop UI design is not as popular as it was back in the 90s mainly because modern applications and games often need to run on a variety of window and screen sizes so they need to be more dynamic than the graphical approach to building them can handle both in terms of sizes and aspect ratios and also in terms of omitting and replacing UI elements on smaller screens.
It's not immediately clear what it is you're trying to achieve, but if you were able to solve it in Godot then you can probably solve it with Bevy it's an ECS based game engine for Rust.
You can find some UI examples here, none specifically show drag and drop as far as I can see. There are separately some examples of picking that you might want to look at