* For now, this is limited to instances inside custom objects. This will be made available in the future for all instances in scenes if this works well.
* This allows playing around with instances directly on the canvas instead of relying on the actions to flip or change opacity and needing to start a preview
* Still to do:
* Properly handle effects (disable 3D effects) for layers
* Handle hot reloading properly
* Avoid duplicating the configuration of the custom object inside each object created from it. Instead, only store the modified values.
* Add a "Extract as a custom object ("prefab")" when selecting instances in a scene.
* Add a dialog to give choice between 2D or 3D object when creating one.
* Make sure "behavior shared data" are properly handled (physics, pathfinding...)
* Check if we need to give an expression to translate coordinates from the parent to the local custom object.
* Ensure a deleted custom object does not break the editor
Co-authored-by: Davy Hélard <davy.helard@gmail.com>